Proposal to amend the PR merge rules

Hi all,

During the weekly dev call, I proposed to amend the PR merge rules,
following an initial comment on Github [
https://github.com/matplotlib/matplotlib/pull/13173#issuecomment-453921220].
There was general agreement among the devs present (Tom, Hannah, Jody, and
myself), so I'm putting it here for discussion. The objective of this
change is to prevent "uncontroversial but uninteresting" PRs from falling
into oblivion, and try to decrease the size of the open PR stack.

The current rule is that a PR needs positive reviews (from two committers,
and excluding the author if a committer) to be merged, except that doc-only
PRs (docstrings, rst) only needs a single positive review.

I am proposing that, if a (non-doc) PR already has one positive review, but
no activity on that PR has occurred for two weeks (exact time interval up
to bikeshedding) [Jody suggests: and the PR has 100% code coverage], then a
committer (either the first reviewer, or the author if a committer) can
suggest that it be merged on the basis of that single review. To do so,
the "sponsor" should ping all developers (@matplotlib/developers) on that
issue indicating that intent, and add a "single-review-merge" label on the
PR (so that these PRs can easily be found). Committers are encouraged to
review the PR to accept and merge it or reject it or request changes on it;
but they can also just indicate that they consider the PR sufficiently
complex that a proper second review is needed before merging, or request an
extension, etc. To do so they should still leave a "reject" review, even
if just saying "objecting to single-review merged; anyone can dismiss after
a second review". However, if within another two weeks, no committer
voiced any objection (explicitly, i.e. by rejecting), then the PR can
indeed be merged on the basis of that single review.

To avoid overwhelming the system, any committer can only "sponsor" a single
PR at a time.

Thoughts?

Antony
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Hello,

Overall, I think this is a good idea, but I would like specifics on what
"uncontroversial but uninteresting" PR mean. IMO, that should exclude any
PR with API changes.

Cheers,
N

···

On Tue, 15 Jan 2019 at 06:00, Antony Lee <anntzer.lee at gmail.com> wrote:

Hi all,

During the weekly dev call, I proposed to amend the PR merge rules,
following an initial comment on Github [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].
There was general agreement among the devs present (Tom, Hannah, Jody, and
myself), so I'm putting it here for discussion. The objective of this
change is to prevent "uncontroversial but uninteresting" PRs from falling
into oblivion, and try to decrease the size of the open PR stack.

The current rule is that a PR needs positive reviews (from two committers,
and excluding the author if a committer) to be merged, except that doc-only
PRs (docstrings, rst) only needs a single positive review.

I am proposing that, if a (non-doc) PR already has one positive review,
but no activity on that PR has occurred for two weeks (exact time interval
up to bikeshedding) [Jody suggests: and the PR has 100% code coverage],
then a committer (either the first reviewer, or the author if a committer)
can suggest that it be merged on the basis of that single review. To do
so, the "sponsor" should ping all developers (@matplotlib/developers) on
that issue indicating that intent, and add a "single-review-merge" label on
the PR (so that these PRs can easily be found). Committers are encouraged
to review the PR to accept and merge it or reject it or request changes on
it; but they can also just indicate that they consider the PR sufficiently
complex that a proper second review is needed before merging, or request an
extension, etc. To do so they should still leave a "reject" review, even
if just saying "objecting to single-review merged; anyone can dismiss after
a second review". However, if within another two weeks, no committer
voiced any objection (explicitly, i.e. by rejecting), then the PR can
indeed be merged on the basis of that single review.

To avoid overwhelming the system, any committer can only "sponsor" a
single PR at a time.

Thoughts?

Antony
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I think this would be a good policy as well. Can I get some clarification
on the flow? The way I understand it:

1) Someone (committer, contributor, or first-timer) opens a simple PR
2) Committer A reviews it, adds a "single-review-merge" label, then
digitally walks away
3) No less than two weeks later, Committer B sees the PR, notices the
label, opens it up, and merges without reviewing.

Does that capture a successful "single-review-merge" lifecycle?
-paul

···

On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux <nelle.varoquaux at gmail.com> wrote:

Hello,

Overall, I think this is a good idea, but I would like specifics on what
"uncontroversial but uninteresting" PR mean. IMO, that should exclude any
PR with API changes.

Cheers,
N

On Tue, 15 Jan 2019 at 06:00, Antony Lee <anntzer.lee at gmail.com> wrote:

Hi all,

During the weekly dev call, I proposed to amend the PR merge rules,
following an initial comment on Github [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].
There was general agreement among the devs present (Tom, Hannah, Jody, and
myself), so I'm putting it here for discussion. The objective of this
change is to prevent "uncontroversial but uninteresting" PRs from falling
into oblivion, and try to decrease the size of the open PR stack.

The current rule is that a PR needs positive reviews (from two
committers, and excluding the author if a committer) to be merged, except
that doc-only PRs (docstrings, rst) only needs a single positive review.

I am proposing that, if a (non-doc) PR already has one positive review,
but no activity on that PR has occurred for two weeks (exact time interval
up to bikeshedding) [Jody suggests: and the PR has 100% code coverage],
then a committer (either the first reviewer, or the author if a committer)
can suggest that it be merged on the basis of that single review. To do
so, the "sponsor" should ping all developers (@matplotlib/developers) on
that issue indicating that intent, and add a "single-review-merge" label on
the PR (so that these PRs can easily be found). Committers are encouraged
to review the PR to accept and merge it or reject it or request changes on
it; but they can also just indicate that they consider the PR sufficiently
complex that a proper second review is needed before merging, or request an
extension, etc. To do so they should still leave a "reject" review, even
if just saying "objecting to single-review merged; anyone can dismiss after
a second review". However, if within another two weeks, no committer
voiced any objection (explicitly, i.e. by rejecting), then the PR can
indeed be merged on the basis of that single review.

To avoid overwhelming the system, any committer can only "sponsor" a
single PR at a time.

Thoughts?

Antony
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I think this would be a good policy as well. Can I get some clarification on the flow? The way I understand it:

1) Someone (committer, contributor, or first-timer) opens a simple PR
2) Committer A reviews it, adds a "single-review-merge" label, then digitally walks away
3) No less than two weeks later, Committer B sees the PR, notices the label, opens it up, and merges without reviewing.

If there is a Committer B, I think they should at least look at the PR to make sure it doesn?t have any hidden API changes, or introduce anything hostile.

The point here is that getting the third person to look at a PR is proving quite difficult, and if the rest of the folks with the commit bit haven?t looked at a PR for a month, even after being warned, then silence indicates consent.

Note that only folks with the commit bit can label PRs, so anyone flagging a PR like this is implicitly trusted to not be wreaking havoc, and not doing this for major changes. Since we all curate our own PRs, I rather expect that the PR contributor will often be the person who adds the flag. Whether we want to allow a self-merge at that point is up for debate, but if not, then folks need to get in the habit of looking at old flagged PRs and merging them.

I think a huge problem we have is the LIFO default sort of the github PR queue, and that any PR not on the first page might as well be closed for all the attention it will get without constant nagging.

Cheers, Jody

···

On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com> wrote:

Does that capture a successful "single-review-merge" lifecycle?
-paul

On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> wrote:
Hello,

Overall, I think this is a good idea, but I would like specifics on what "uncontroversial but uninteresting" PR mean. IMO, that should exclude any PR with API changes.

Cheers,
N

On Tue, 15 Jan 2019 at 06:00, Antony Lee <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> wrote:
Hi all,

During the weekly dev call, I proposed to amend the PR merge rules, following an initial comment on Github [Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub]. There was general agreement among the devs present (Tom, Hannah, Jody, and myself), so I'm putting it here for discussion. The objective of this change is to prevent "uncontroversial but uninteresting" PRs from falling into oblivion, and try to decrease the size of the open PR stack.

The current rule is that a PR needs positive reviews (from two committers, and excluding the author if a committer) to be merged, except that doc-only PRs (docstrings, rst) only needs a single positive review.

I am proposing that, if a (non-doc) PR already has one positive review, but no activity on that PR has occurred for two weeks (exact time interval up to bikeshedding) [Jody suggests: and the PR has 100% code coverage], then a committer (either the first reviewer, or the author if a committer) can suggest that it be merged on the basis of that single review. To do so, the "sponsor" should ping all developers (@matplotlib/developers) on that issue indicating that intent, and add a "single-review-merge" label on the PR (so that these PRs can easily be found). Committers are encouraged to review the PR to accept and merge it or reject it or request changes on it; but they can also just indicate that they consider the PR sufficiently complex that a proper second review is needed before merging, or request an extension, etc. To do so they should still leave a "reject" review, even if just saying "objecting to single-review merged; anyone can dismiss after a second review". However, if within another two weeks, no committer voiced any objection (explicitly, i.e. by rejecting), then the PR can indeed be merged on the basis of that single review.

To avoid overwhelming the system, any committer can only "sponsor" a single PR at a time.

Thoughts?

Antony
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The proposed scheme by Paul doesn't seem reasonable to me. Core contributor
A or committers needs to actively reach out to other core contributors:
labeling is not enough IMO.

···

On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca> wrote:

On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com> wrote:

I think this would be a good policy as well. Can I get some clarification
on the flow? The way I understand it:

1) Someone (committer, contributor, or first-timer) opens a simple PR
2) Committer A reviews it, adds a "single-review-merge" label, then
digitally walks away
3) No less than two weeks later, Committer B sees the PR, notices the
label, opens it up, and merges without reviewing.

If there is a Committer B, I think they should at least look at the PR to
make sure it doesn?t have any hidden API changes, or introduce anything
hostile.

The point here is that getting the third person to look at a PR is proving
quite difficult, and if the rest of the folks with the commit bit haven?t
looked at a PR for a month, even after being warned, then silence indicates
consent.

Note that only folks with the commit bit can label PRs, so anyone flagging
a PR like this is implicitly trusted to not be wreaking havoc, and not
doing this for major changes. Since we all curate our own PRs, I rather
expect that the PR contributor will often be the person who adds the flag.
Whether we want to allow a self-merge at that point is up for debate, but
if not, then folks need to get in the habit of looking at old flagged PRs
and merging them.

I think a huge problem we have is the LIFO default sort of the github PR
queue, and that any PR not on the first page might as well be closed for
all the attention it will get without constant nagging.

Cheers, Jody

Does that capture a successful "single-review-merge" lifecycle?
-paul

On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux <nelle.varoquaux at gmail.com> > wrote:

Hello,

Overall, I think this is a good idea, but I would like specifics on what
"uncontroversial but uninteresting" PR mean. IMO, that should exclude any
PR with API changes.

Cheers,
N

On Tue, 15 Jan 2019 at 06:00, Antony Lee <anntzer.lee at gmail.com> wrote:

Hi all,

During the weekly dev call, I proposed to amend the PR merge rules,
following an initial comment on Github [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].
There was general agreement among the devs present (Tom, Hannah, Jody, and
myself), so I'm putting it here for discussion. The objective of this
change is to prevent "uncontroversial but uninteresting" PRs from falling
into oblivion, and try to decrease the size of the open PR stack.

The current rule is that a PR needs positive reviews (from two
committers, and excluding the author if a committer) to be merged, except
that doc-only PRs (docstrings, rst) only needs a single positive review.

I am proposing that, if a (non-doc) PR already has one positive review,
but no activity on that PR has occurred for two weeks (exact time interval
up to bikeshedding) [Jody suggests: and the PR has 100% code coverage],
then a committer (either the first reviewer, or the author if a committer)
can suggest that it be merged on the basis of that single review. To do
so, the "sponsor" should ping all developers (@matplotlib/developers) on
that issue indicating that intent, and add a "single-review-merge" label on
the PR (so that these PRs can easily be found). Committers are encouraged
to review the PR to accept and merge it or reject it or request changes on
it; but they can also just indicate that they consider the PR sufficiently
complex that a proper second review is needed before merging, or request an
extension, etc. To do so they should still leave a "reject" review, even
if just saying "objecting to single-review merged; anyone can dismiss after
a second review". However, if within another two weeks, no committer
voiced any objection (explicitly, i.e. by rejecting), then the PR can
indeed be merged on the basis of that single review.

To avoid overwhelming the system, any committer can only "sponsor" a
single PR at a time.

Thoughts?

Antony
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Matplotlib-devel Info Page

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Jody M. Klymak - UVic Ocean Physics

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I'm obviously more aware of my own PRs, so here are a few I'd have put up
for single-review-merge (note that it's quite possible that they'd have
attracted more attention and gotten merged faster under that system; that's
also the goal...). Obviously other devs may think about other PRs that
could have benefitted from the same process.

- Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support for the
ttc font format (requested since 2014) for png/svg output (that's provided
basically for free by FreeType) but not for pdf/ps (that would require more
difficult changes). The entire PR comes down to:
  * adding "ttc" as an extension that should be treated like "ttf"/"otf",
  * adding error handling to pdf/ps to signal these formats are not
supported there,
  * tests.
  The PR sat open for 10 months before a first positive review (because no
one cares about fonts, I guess) and took another 3 months to attract a
second positive review.

- Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a fairly trivial
fix to fontList.json to make it reusable for Matplotlibs installed in
different venvs, got a positive review in one day and waited another 2.5
months for a second positive review.

- Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
completely duplicated code between the pdf and ps backends, mostly for
maintainability's sake; it took 7.5 months (and 5 rebases due to conflicts)
to get a first positive review and another 6 (and around as many rebases)
to get a second one.

···

-----

As for the specifics (as I see it):
- Someone opens a PR, it gets a positive review, no negative review, and no
activity occurs for two weeks (significant activity -- excluding trivial
chat on the thread).
- Sponsor (first reviewer, or author if a committer) *pings* all devs by
mentioning @matplotlib/developers on the PR thread with the intent to
single-review-merge, and labels the PR accordingly.
- The PR can still be reviewed/merged/rejected by the normal review
process. However, if no one explicitly opposes the merge within two weeks,
anyone can merge it at that point (including by self-merge).

I would not exclude all API changes from the process. For example,
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
deprecates (and prepares for deletion) two parameters to imshow() that have
had no effect since 2006. Let's pretend for a second this commit was a
single independent PR (and not an example to showcase the
parameter-deprecating decorator...); if it started being forgotten I would
have proposed it for single-review-merge (again, note that if you're
worried about the change, you don't need to reject the PR; you can just
say, I think this API change needs to be approved by a second reviewer and
that'll block the single-review-merge just as well).

Antony

On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux <nelle.varoquaux at gmail.com> wrote:

The proposed scheme by Paul doesn't seem reasonable to me. Core
contributor A or committers needs to actively reach out to other core
contributors: labeling is not enough IMO.

On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca> wrote:

On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com> wrote:

I think this would be a good policy as well. Can I get some clarification
on the flow? The way I understand it:

1) Someone (committer, contributor, or first-timer) opens a simple PR
2) Committer A reviews it, adds a "single-review-merge" label, then
digitally walks away
3) No less than two weeks later, Committer B sees the PR, notices the
label, opens it up, and merges without reviewing.

If there is a Committer B, I think they should at least look at the PR to
make sure it doesn?t have any hidden API changes, or introduce anything
hostile.

The point here is that getting the third person to look at a PR is
proving quite difficult, and if the rest of the folks with the commit bit
haven?t looked at a PR for a month, even after being warned, then silence
indicates consent.

Note that only folks with the commit bit can label PRs, so anyone
flagging a PR like this is implicitly trusted to not be wreaking havoc, and
not doing this for major changes. Since we all curate our own PRs, I
rather expect that the PR contributor will often be the person who adds the
flag. Whether we want to allow a self-merge at that point is up for
debate, but if not, then folks need to get in the habit of looking at old
flagged PRs and merging them.

I think a huge problem we have is the LIFO default sort of the github PR
queue, and that any PR not on the first page might as well be closed for
all the attention it will get without constant nagging.

Cheers, Jody

Does that capture a successful "single-review-merge" lifecycle?
-paul

On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux < >> nelle.varoquaux at gmail.com> wrote:

Hello,

Overall, I think this is a good idea, but I would like specifics on what
"uncontroversial but uninteresting" PR mean. IMO, that should exclude any
PR with API changes.

Cheers,
N

On Tue, 15 Jan 2019 at 06:00, Antony Lee <anntzer.lee at gmail.com> wrote:

Hi all,

During the weekly dev call, I proposed to amend the PR merge rules,
following an initial comment on Github [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].
There was general agreement among the devs present (Tom, Hannah, Jody, and
myself), so I'm putting it here for discussion. The objective of this
change is to prevent "uncontroversial but uninteresting" PRs from falling
into oblivion, and try to decrease the size of the open PR stack.

The current rule is that a PR needs positive reviews (from two
committers, and excluding the author if a committer) to be merged, except
that doc-only PRs (docstrings, rst) only needs a single positive review.

I am proposing that, if a (non-doc) PR already has one positive review,
but no activity on that PR has occurred for two weeks (exact time interval
up to bikeshedding) [Jody suggests: and the PR has 100% code coverage],
then a committer (either the first reviewer, or the author if a committer)
can suggest that it be merged on the basis of that single review. To do
so, the "sponsor" should ping all developers (@matplotlib/developers) on
that issue indicating that intent, and add a "single-review-merge" label on
the PR (so that these PRs can easily be found). Committers are encouraged
to review the PR to accept and merge it or reject it or request changes on
it; but they can also just indicate that they consider the PR sufficiently
complex that a proper second review is needed before merging, or request an
extension, etc. To do so they should still leave a "reject" review, even
if just saying "objecting to single-review merged; anyone can dismiss after
a second review". However, if within another two weeks, no committer
voiced any objection (explicitly, i.e. by rejecting), then the PR can
indeed be merged on the basis of that single review.

To avoid overwhelming the system, any committer can only "sponsor" a
single PR at a time.

Thoughts?

Antony
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Matplotlib-devel at python.org
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Matplotlib-devel at python.org
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Jody Klymak
Jody M. Klymak - UVic Ocean Physics

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Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable time.

I'm fine with your proposed rule. It should help at least a little bit.

Eric

···

On 2019/01/15 9:11 AM, Antony Lee wrote:

I'm obviously more aware of my own PRs, so here are a few I'd have put
up for single-review-merge (note that it's quite possible that they'd
have attracted more attention and gotten merged faster under that
system; that's also the goal...).? Obviously other devs may think about
other PRs that could have benefitted from the same process.

- Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support for
the ttc font format (requested since 2014) for png/svg output (that's
provided basically for free by FreeType) but not for pdf/ps (that would
require more difficult changes).? The entire PR comes down to:
? * adding "ttc" as an extension that should be treated like "ttf"/"otf",
? * adding error handling to pdf/ps to signal these formats are not
supported there,
? * tests.
? The PR sat open for 10 months before a first positive review (because
no one cares about fonts, I guess) and took another 3 months to attract
a second positive review.

- Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a fairly
trivial fix to fontList.json to make it reusable for Matplotlibs
installed in different venvs, got a positive review in one day and
waited another 2.5 months for a second positive review.

- Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
completely duplicated code between the pdf and ps backends, mostly for
maintainability's sake; it took 7.5 months (and 5 rebases due to
conflicts) to get a first positive review and another 6 (and around as
many rebases) to get a second one.

-----

As for the specifics (as I see it):
- Someone opens a PR, it gets a positive review, no negative review, and
no activity occurs for two weeks (significant activity -- excluding
trivial chat on the thread).
- Sponsor (first reviewer, or author if a committer) *pings* all devs by
mentioning @matplotlib/developers on the PR thread with the intent to
single-review-merge, and labels the PR accordingly.
- The PR can still be reviewed/merged/rejected by the normal review
process.? However, if no one explicitly opposes the merge within two
weeks, anyone can merge it at that point (including by self-merge).

I would not exclude all API changes from the process.? For example,
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
deprecates (and prepares for deletion) two parameters to imshow() that
have had no effect since 2006.? Let's pretend for a second this commit
was a single independent PR (and not an example to showcase the
parameter-deprecating decorator...); if it started being forgotten I
would have proposed it for single-review-merge (again, note that if
you're worried about the change, you don't need to reject the PR; you
can just say, I think this API change needs to be approved by a second
reviewer and that'll block the single-review-merge just as well).

Antony

On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> wrote:

    The proposed scheme by Paul doesn't seem reasonable to me. Core
    contributor A or committers needs to actively reach out to other
    core contributors: labeling is not enough IMO.

    On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca > <mailto:jklymak at uvic.ca>> wrote:

        On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com >> <mailto:pmhobson at gmail.com>> wrote:

        I think this would be a good policy as well. Can I get some
        clarification on the flow? The way I understand it:

        1) Someone (committer, contributor, or first-timer) opens a
        simple PR
        2) Committer A reviews it, adds a "single-review-merge" label,
        then digitally walks away
        3) No less than two weeks later, Committer B sees the PR,
        notices the label, opens it up, and merges without reviewing.

        If there is a Committer B, I think they should at least look at
        the PR to make sure it doesn?t have any hidden API changes, or
        introduce anything hostile.

        The point here is that getting the third person to look at a PR
        is proving quite difficult, and if the rest of the folks with
        the commit bit haven?t looked at a PR for a month, even after
        being warned, then silence indicates consent.

        Note that only folks with the commit bit can label PRs, so
        anyone flagging a PR like this is implicitly trusted to not be
        wreaking havoc, and not doing this for major changes.? Since we
        all curate our own PRs, I rather expect that the PR contributor
        will often be the person who adds the flag.? Whether we want to
        allow a self-merge at that point is up for debate, but if not,
        then folks need to get in the habit of looking at old flagged
        PRs and merging them.

        I think a huge problem we have is the LIFO default sort of the
        github PR queue, and that any PR not on the first page might as
        well be closed for all the attention it will get without
        constant nagging.

        Cheers, ? Jody

        Does that capture a successful "single-review-merge" lifecycle?
        -paul

        On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux >> <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> >> wrote:

            Hello,

            Overall, I think this is a good idea, but I would like
            specifics on what "uncontroversial but uninteresting" PR
            mean. IMO, that should exclude any PR with API changes.

            Cheers,
            N

            On Tue, 15 Jan 2019 at 06:00, Antony Lee >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> wrote:

                Hi all,

                During the weekly dev call, I proposed to amend the PR
                merge rules, following an initial comment on Github
                [Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].
                There was general agreement among the devs present
                (Tom, Hannah, Jody, and myself), so I'm putting it
                here for discussion.? The objective of this change is
                to prevent "uncontroversial but uninteresting" PRs
                from falling into oblivion, and try to decrease the
                size of the open PR stack.

                The current rule is that a PR needs positive reviews
                (from two committers, and excluding the author if a
                committer) to be merged, except that doc-only PRs
                (docstrings, rst) only needs a single positive review.

                I am proposing that, if a (non-doc) PR already has one
                positive review, but no activity on that PR has
                occurred for two weeks (exact time interval up to
                bikeshedding) [Jody suggests: and the PR has 100% code
                coverage], then a committer (either the first
                reviewer, or the author if a committer) can suggest
                that it be merged on the basis of that single review.
                To do so, the "sponsor" should ping all developers
                (@matplotlib/developers) on that issue indicating that
                intent, and add a "single-review-merge" label on the
                PR (so that these PRs can easily be found).
                Committers are encouraged to review the PR to accept
                and merge it or reject it or request changes on it;
                but they can also just indicate that they consider the
                PR sufficiently complex that a proper second review is
                needed before merging, or request an extension, etc.
                To do so they should still leave a "reject" review,
                even if just saying "objecting to single-review
                merged; anyone can dismiss after a second review".
                However, if within another two weeks, no committer
                voiced any objection (explicitly, i.e. by rejecting),
                then the PR can indeed be merged on the basis of that
                single review.

                To avoid overwhelming the system, any committer can
                only "sponsor" a single PR at a time.

                Thoughts?

                Antony
                _______________________________________________
                Matplotlib-devel mailing list
                Matplotlib-devel at python.org
                <mailto:Matplotlib-devel at python.org>
                Matplotlib-devel Info Page

            _______________________________________________
            Matplotlib-devel mailing list
            Matplotlib-devel at python.org
            <mailto:Matplotlib-devel at python.org>
            Matplotlib-devel Info Page

        _______________________________________________
        Matplotlib-devel mailing list
        Matplotlib-devel at python.org <mailto:Matplotlib-devel at python.org>
        Matplotlib-devel Info Page

        --
        Jody Klymak
        Jody M. Klymak - UVic Ocean Physics

    _______________________________________________
    Matplotlib-devel mailing list
    Matplotlib-devel at python.org <mailto:Matplotlib-devel at python.org>
    Matplotlib-devel Info Page

_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel at python.org
Matplotlib-devel Info Page

Eric,
Neither the ttc font, nor the pdf/ps common code PRs actually touch any
"complex" point regarding fonts or pdf/ps. I have described the ttc font
in my previous message; the pdf/ps PR is really just, look, these two
classes share 80 lines worth of code that's literally copy-pasted, let's
just put that in a common parent class and inherit from it.
Conversely, one font-related PR for which I actually have low hopes of
getting properly reviewed (except on an "sure, I trust you" basis) is
textpath encoding by anntzer · Pull Request #12928 · matplotlib/matplotlib · GitHub, which actually touches
a rather complex point about font encodings (some of which I had to clarify
on the FreeType mailing list). (If anyone wants to have a look at it,
though... :p)
Antony

···

On Tue, Jan 15, 2019 at 10:36 PM Eric Firing <efiring at hawaii.edu> wrote:

Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable time.

I'm fine with your proposed rule. It should help at least a little bit.

Eric

On 2019/01/15 9:11 AM, Antony Lee wrote:
> I'm obviously more aware of my own PRs, so here are a few I'd have put
> up for single-review-merge (note that it's quite possible that they'd
> have attracted more attention and gotten merged faster under that
> system; that's also the goal...). Obviously other devs may think about
> other PRs that could have benefitted from the same process.
>
> - Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support for
> the ttc font format (requested since 2014) for png/svg output (that's
> provided basically for free by FreeType) but not for pdf/ps (that would
> require more difficult changes). The entire PR comes down to:
> * adding "ttc" as an extension that should be treated like
"ttf"/"otf",
> * adding error handling to pdf/ps to signal these formats are not
> supported there,
> * tests.
> The PR sat open for 10 months before a first positive review (because
> no one cares about fonts, I guess) and took another 3 months to attract
> a second positive review.
>
> - Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a fairly
> trivial fix to fontList.json to make it reusable for Matplotlibs
> installed in different venvs, got a positive review in one day and
> waited another 2.5 months for a second positive review.
>
> - Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
> completely duplicated code between the pdf and ps backends, mostly for
> maintainability's sake; it took 7.5 months (and 5 rebases due to
> conflicts) to get a first positive review and another 6 (and around as
> many rebases) to get a second one.
>
> -----
>
> As for the specifics (as I see it):
> - Someone opens a PR, it gets a positive review, no negative review, and
> no activity occurs for two weeks (significant activity -- excluding
> trivial chat on the thread).
> - Sponsor (first reviewer, or author if a committer) *pings* all devs by
> mentioning @matplotlib/developers on the PR thread with the intent to
> single-review-merge, and labels the PR accordingly.
> - The PR can still be reviewed/merged/rejected by the normal review
> process. However, if no one explicitly opposes the merge within two
> weeks, anyone can merge it at that point (including by self-merge).
>
> I would not exclude all API changes from the process. For example,
>
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
> deprecates (and prepares for deletion) two parameters to imshow() that
> have had no effect since 2006. Let's pretend for a second this commit
> was a single independent PR (and not an example to showcase the
> parameter-deprecating decorator...); if it started being forgotten I
> would have proposed it for single-review-merge (again, note that if
> you're worried about the change, you don't need to reject the PR; you
> can just say, I think this API change needs to be approved by a second
> reviewer and that'll block the single-review-merge just as well).
>
> Antony
>
> On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux > > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> wrote:
>
> The proposed scheme by Paul doesn't seem reasonable to me. Core
> contributor A or committers needs to actively reach out to other
> core contributors: labeling is not enough IMO.
>
>
> On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca > > <mailto:jklymak at uvic.ca>> wrote:
>
>
>
>> On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com > >> <mailto:pmhobson at gmail.com>> wrote:
>>
>> I think this would be a good policy as well. Can I get some
>> clarification on the flow? The way I understand it:
>>
>> 1) Someone (committer, contributor, or first-timer) opens a
>> simple PR
>> 2) Committer A reviews it, adds a "single-review-merge" label,
>> then digitally walks away
>> 3) No less than two weeks later, Committer B sees the PR,
>> notices the label, opens it up, and merges without reviewing.
>
> If there is a Committer B, I think they should at least look at
> the PR to make sure it doesn?t have any hidden API changes, or
> introduce anything hostile.
>
> The point here is that getting the third person to look at a PR
> is proving quite difficult, and if the rest of the folks with
> the commit bit haven?t looked at a PR for a month, even after
> being warned, then silence indicates consent.
>
> Note that only folks with the commit bit can label PRs, so
> anyone flagging a PR like this is implicitly trusted to not be
> wreaking havoc, and not doing this for major changes. Since we
> all curate our own PRs, I rather expect that the PR contributor
> will often be the person who adds the flag. Whether we want to
> allow a self-merge at that point is up for debate, but if not,
> then folks need to get in the habit of looking at old flagged
> PRs and merging them.
>
> I think a huge problem we have is the LIFO default sort of the
> github PR queue, and that any PR not on the first page might as
> well be closed for all the attention it will get without
> constant nagging.
>
> Cheers, Jody
>
>> Does that capture a successful "single-review-merge" lifecycle?
>> -paul
>>
>> On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux > >> <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> > >> wrote:
>>
>> Hello,
>>
>> Overall, I think this is a good idea, but I would like
>> specifics on what "uncontroversial but uninteresting" PR
>> mean. IMO, that should exclude any PR with API changes.
>>
>> Cheers,
>> N
>>
>> On Tue, 15 Jan 2019 at 06:00, Antony Lee > >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> > wrote:
>>
>> Hi all,
>>
>> During the weekly dev call, I proposed to amend the PR
>> merge rules, following an initial comment on Github
>> [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].

>> There was general agreement among the devs present
>> (Tom, Hannah, Jody, and myself), so I'm putting it
>> here for discussion. The objective of this change is
>> to prevent "uncontroversial but uninteresting" PRs
>> from falling into oblivion, and try to decrease the
>> size of the open PR stack.
>>
>> The current rule is that a PR needs positive reviews
>> (from two committers, and excluding the author if a
>> committer) to be merged, except that doc-only PRs
>> (docstrings, rst) only needs a single positive review.
>>
>> I am proposing that, if a (non-doc) PR already has one
>> positive review, but no activity on that PR has
>> occurred for two weeks (exact time interval up to
>> bikeshedding) [Jody suggests: and the PR has 100% code
>> coverage], then a committer (either the first
>> reviewer, or the author if a committer) can suggest
>> that it be merged on the basis of that single review.
>> To do so, the "sponsor" should ping all developers
>> (@matplotlib/developers) on that issue indicating that
>> intent, and add a "single-review-merge" label on the
>> PR (so that these PRs can easily be found).
>> Committers are encouraged to review the PR to accept
>> and merge it or reject it or request changes on it;
>> but they can also just indicate that they consider the
>> PR sufficiently complex that a proper second review is
>> needed before merging, or request an extension, etc.
>> To do so they should still leave a "reject" review,
>> even if just saying "objecting to single-review
>> merged; anyone can dismiss after a second review".
>> However, if within another two weeks, no committer
>> voiced any objection (explicitly, i.e. by rejecting),
>> then the PR can indeed be merged on the basis of that
>> single review.
>>
>> To avoid overwhelming the system, any committer can
>> only "sponsor" a single PR at a time.
>>
>> Thoughts?
>>
>> Antony
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>>
Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>> Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org <mailto:Matplotlib-devel at python.org
>
>> Matplotlib-devel Info Page
>
> --
> Jody Klymak
> Jody M. Klymak - UVic Ocean Physics
>
>
>
>
>
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel at python.org <mailto:Matplotlib-devel at python.org>
> Matplotlib-devel Info Page
>
>
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel at python.org
> Matplotlib-devel Info Page
>

_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel at python.org
Matplotlib-devel Info Page

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I understand. Nevertheless, there is an understandable tendency for
someone like me to look at such a PR and back off, hoping someone more
familiar with those areas will take care of it. I think your proposal
will help with this problem.

Eric

···

On 2019/01/15 11:44 AM, Antony Lee wrote:

Neither the ttc font, nor the pdf/ps common code PRs actually touch any
"complex" point regarding fonts or pdf/ps.

I think a distinction between "no one cares" and "no one has bandwidth"
needs to be made.

If you look at the 'pulse' page, we merging 100+ PRs a month (
Pulse · matplotlib/matplotlib · GitHub) so reviews are
happening, the issue is just that some are falling through the cracks.

Tom

···

On Tue, Jan 15, 2019 at 4:45 PM Antony Lee <antony.lee at institutoptique.fr> wrote:

Eric,
Neither the ttc font, nor the pdf/ps common code PRs actually touch any
"complex" point regarding fonts or pdf/ps. I have described the ttc font
in my previous message; the pdf/ps PR is really just, look, these two
classes share 80 lines worth of code that's literally copy-pasted, let's
just put that in a common parent class and inherit from it.
Conversely, one font-related PR for which I actually have low hopes of
getting properly reviewed (except on an "sure, I trust you" basis) is
textpath encoding by anntzer · Pull Request #12928 · matplotlib/matplotlib · GitHub, which actually
touches a rather complex point about font encodings (some of which I had to
clarify on the FreeType mailing list). (If anyone wants to have a look at
it, though... :p)
Antony

On Tue, Jan 15, 2019 at 10:36 PM Eric Firing <efiring at hawaii.edu> wrote:

Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable time.

I'm fine with your proposed rule. It should help at least a little bit.

Eric

On 2019/01/15 9:11 AM, Antony Lee wrote:
> I'm obviously more aware of my own PRs, so here are a few I'd have put
> up for single-review-merge (note that it's quite possible that they'd
> have attracted more attention and gotten merged faster under that
> system; that's also the goal...). Obviously other devs may think about
> other PRs that could have benefitted from the same process.
>
> - Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support for
> the ttc font format (requested since 2014) for png/svg output (that's
> provided basically for free by FreeType) but not for pdf/ps (that would
> require more difficult changes). The entire PR comes down to:
> * adding "ttc" as an extension that should be treated like
"ttf"/"otf",
> * adding error handling to pdf/ps to signal these formats are not
> supported there,
> * tests.
> The PR sat open for 10 months before a first positive review
(because
> no one cares about fonts, I guess) and took another 3 months to attract
> a second positive review.
>
> - Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a fairly
> trivial fix to fontList.json to make it reusable for Matplotlibs
> installed in different venvs, got a positive review in one day and
> waited another 2.5 months for a second positive review.
>
> - Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
> completely duplicated code between the pdf and ps backends, mostly for
> maintainability's sake; it took 7.5 months (and 5 rebases due to
> conflicts) to get a first positive review and another 6 (and around as
> many rebases) to get a second one.
>
> -----
>
> As for the specifics (as I see it):
> - Someone opens a PR, it gets a positive review, no negative review,
and
> no activity occurs for two weeks (significant activity -- excluding
> trivial chat on the thread).
> - Sponsor (first reviewer, or author if a committer) *pings* all devs
by
> mentioning @matplotlib/developers on the PR thread with the intent to
> single-review-merge, and labels the PR accordingly.
> - The PR can still be reviewed/merged/rejected by the normal review
> process. However, if no one explicitly opposes the merge within two
> weeks, anyone can merge it at that point (including by self-merge).
>
> I would not exclude all API changes from the process. For example,
>
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
> deprecates (and prepares for deletion) two parameters to imshow() that
> have had no effect since 2006. Let's pretend for a second this commit
> was a single independent PR (and not an example to showcase the
> parameter-deprecating decorator...); if it started being forgotten I
> would have proposed it for single-review-merge (again, note that if
> you're worried about the change, you don't need to reject the PR; you
> can just say, I think this API change needs to be approved by a second
> reviewer and that'll block the single-review-merge just as well).
>
> Antony
>
> On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux >> > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> wrote:
>
> The proposed scheme by Paul doesn't seem reasonable to me. Core
> contributor A or committers needs to actively reach out to other
> core contributors: labeling is not enough IMO.
>
>
> On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca >> > <mailto:jklymak at uvic.ca>> wrote:
>
>
>
>> On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com >> >> <mailto:pmhobson at gmail.com>> wrote:
>>
>> I think this would be a good policy as well. Can I get some
>> clarification on the flow? The way I understand it:
>>
>> 1) Someone (committer, contributor, or first-timer) opens a
>> simple PR
>> 2) Committer A reviews it, adds a "single-review-merge" label,
>> then digitally walks away
>> 3) No less than two weeks later, Committer B sees the PR,
>> notices the label, opens it up, and merges without reviewing.
>
> If there is a Committer B, I think they should at least look at
> the PR to make sure it doesn?t have any hidden API changes, or
> introduce anything hostile.
>
> The point here is that getting the third person to look at a PR
> is proving quite difficult, and if the rest of the folks with
> the commit bit haven?t looked at a PR for a month, even after
> being warned, then silence indicates consent.
>
> Note that only folks with the commit bit can label PRs, so
> anyone flagging a PR like this is implicitly trusted to not be
> wreaking havoc, and not doing this for major changes. Since we
> all curate our own PRs, I rather expect that the PR contributor
> will often be the person who adds the flag. Whether we want to
> allow a self-merge at that point is up for debate, but if not,
> then folks need to get in the habit of looking at old flagged
> PRs and merging them.
>
> I think a huge problem we have is the LIFO default sort of the
> github PR queue, and that any PR not on the first page might as
> well be closed for all the attention it will get without
> constant nagging.
>
> Cheers, Jody
>
>> Does that capture a successful "single-review-merge" lifecycle?
>> -paul
>>
>> On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux >> >> <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> >> >> wrote:
>>
>> Hello,
>>
>> Overall, I think this is a good idea, but I would like
>> specifics on what "uncontroversial but uninteresting" PR
>> mean. IMO, that should exclude any PR with API changes.
>>
>> Cheers,
>> N
>>
>> On Tue, 15 Jan 2019 at 06:00, Antony Lee >> >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> >> wrote:
>>
>> Hi all,
>>
>> During the weekly dev call, I proposed to amend the PR
>> merge rules, following an initial comment on Github
>> [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].

>> There was general agreement among the devs present
>> (Tom, Hannah, Jody, and myself), so I'm putting it
>> here for discussion. The objective of this change is
>> to prevent "uncontroversial but uninteresting" PRs
>> from falling into oblivion, and try to decrease the
>> size of the open PR stack.
>>
>> The current rule is that a PR needs positive reviews
>> (from two committers, and excluding the author if a
>> committer) to be merged, except that doc-only PRs
>> (docstrings, rst) only needs a single positive review.
>>
>> I am proposing that, if a (non-doc) PR already has one
>> positive review, but no activity on that PR has
>> occurred for two weeks (exact time interval up to
>> bikeshedding) [Jody suggests: and the PR has 100% code
>> coverage], then a committer (either the first
>> reviewer, or the author if a committer) can suggest
>> that it be merged on the basis of that single review.
>> To do so, the "sponsor" should ping all developers
>> (@matplotlib/developers) on that issue indicating that
>> intent, and add a "single-review-merge" label on the
>> PR (so that these PRs can easily be found).
>> Committers are encouraged to review the PR to accept
>> and merge it or reject it or request changes on it;
>> but they can also just indicate that they consider the
>> PR sufficiently complex that a proper second review is
>> needed before merging, or request an extension, etc.
>> To do so they should still leave a "reject" review,
>> even if just saying "objecting to single-review
>> merged; anyone can dismiss after a second review".
>> However, if within another two weeks, no committer
>> voiced any objection (explicitly, i.e. by rejecting),
>> then the PR can indeed be merged on the basis of that
>> single review.
>>
>> To avoid overwhelming the system, any committer can
>> only "sponsor" a single PR at a time.
>>
>> Thoughts?
>>
>> Antony
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>>
Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>> Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org <mailto:
Matplotlib-devel at python.org>
>> Matplotlib-devel Info Page
>
> --
> Jody Klymak
> Jody M. Klymak - UVic Ocean Physics
>
>
>
>
>
> _______________________________________________
> Matplotlib-devel mailing list
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> Matplotlib-devel Info Page
>
>
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel at python.org
> Matplotlib-devel Info Page
>

_______________________________________________
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Matplotlib-devel at python.org
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For the way GitHub sorts pull requests, it is indeed a problem, but there's
a way to sort by "most recently updated." I sometimes use it to make sure
that I review recently updated pull request that don't appear on the first
page.

It seems to me that this "uncontroversial but uninteresting" rule is
currently not based on objective criteria. I'm personally not in favor of
removing two core contributors approval for anything that modifies the
API. We have had too many close calls on PR almost merged that had
backward incompatible changes: I realize that some core developers believe
that we are not moving fast enough, on a project with hundreds of thousands
of users, changes to the API should not be considered lightly.

Here's an attempt at better defining an "uncontroversial but uninteresting"
rule based on objective criteria:
- Has not been commented on by more than one core developer;
- Doesn't change the *public* API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;
- Is fully tested;
- All parameters are fully documented;
- Doesn't fix a release-critical bug;
- Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

To be honest, it also doesn't help that some people have 50+ pull requests
open (Antony? :p). It also doesn't help that some PR contain the same code
(13117, 13128) and are being hold off until the other one is merged (also,
why is 13117 being hold off for a PR that has been opened afterwards?).
IMO, if a PR can be merged, it should be merged. But we shouldn't make too
many exceptions to the two core contributors rules. It's easier to have two
core contributor review a pull request, than to try to fix API issues on
code that has been merged and released. Having two pairs of eyes on a PR is
also a good way to avoid having a bus factor of 1 on some areas of the
library.

···

On Tue, 15 Jan 2019 at 15:19, Thomas Caswell <tcaswell at gmail.com> wrote:

I think a distinction between "no one cares" and "no one has bandwidth"
needs to be made.

If you look at the 'pulse' page, we merging 100+ PRs a month (
Pulse · matplotlib/matplotlib · GitHub) so reviews are
happening, the issue is just that some are falling through the cracks.

Tom

On Tue, Jan 15, 2019 at 4:45 PM Antony Lee <antony.lee at institutoptique.fr> > wrote:

Eric,
Neither the ttc font, nor the pdf/ps common code PRs actually touch any
"complex" point regarding fonts or pdf/ps. I have described the ttc font
in my previous message; the pdf/ps PR is really just, look, these two
classes share 80 lines worth of code that's literally copy-pasted, let's
just put that in a common parent class and inherit from it.
Conversely, one font-related PR for which I actually have low hopes of
getting properly reviewed (except on an "sure, I trust you" basis) is
textpath encoding by anntzer · Pull Request #12928 · matplotlib/matplotlib · GitHub, which actually
touches a rather complex point about font encodings (some of which I had to
clarify on the FreeType mailing list). (If anyone wants to have a look at
it, though... :p)
Antony

On Tue, Jan 15, 2019 at 10:36 PM Eric Firing <efiring at hawaii.edu> wrote:

Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable
time.

I'm fine with your proposed rule. It should help at least a little bit.

Eric

On 2019/01/15 9:11 AM, Antony Lee wrote:
> I'm obviously more aware of my own PRs, so here are a few I'd have put
> up for single-review-merge (note that it's quite possible that they'd
> have attracted more attention and gotten merged faster under that
> system; that's also the goal...). Obviously other devs may think
about
> other PRs that could have benefitted from the same process.
>
> - Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support for
> the ttc font format (requested since 2014) for png/svg output (that's
> provided basically for free by FreeType) but not for pdf/ps (that
would
> require more difficult changes). The entire PR comes down to:
> * adding "ttc" as an extension that should be treated like
"ttf"/"otf",
> * adding error handling to pdf/ps to signal these formats are not
> supported there,
> * tests.
> The PR sat open for 10 months before a first positive review
(because
> no one cares about fonts, I guess) and took another 3 months to
attract
> a second positive review.
>
> - Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a fairly
> trivial fix to fontList.json to make it reusable for Matplotlibs
> installed in different venvs, got a positive review in one day and
> waited another 2.5 months for a second positive review.
>
> - Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
> completely duplicated code between the pdf and ps backends, mostly for
> maintainability's sake; it took 7.5 months (and 5 rebases due to
> conflicts) to get a first positive review and another 6 (and around as
> many rebases) to get a second one.
>
> -----
>
> As for the specifics (as I see it):
> - Someone opens a PR, it gets a positive review, no negative review,
and
> no activity occurs for two weeks (significant activity -- excluding
> trivial chat on the thread).
> - Sponsor (first reviewer, or author if a committer) *pings* all devs
by
> mentioning @matplotlib/developers on the PR thread with the intent to
> single-review-merge, and labels the PR accordingly.
> - The PR can still be reviewed/merged/rejected by the normal review
> process. However, if no one explicitly opposes the merge within two
> weeks, anyone can merge it at that point (including by self-merge).
>
> I would not exclude all API changes from the process. For example,
>
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
> deprecates (and prepares for deletion) two parameters to imshow() that
> have had no effect since 2006. Let's pretend for a second this commit
> was a single independent PR (and not an example to showcase the
> parameter-deprecating decorator...); if it started being forgotten I
> would have proposed it for single-review-merge (again, note that if
> you're worried about the change, you don't need to reject the PR; you
> can just say, I think this API change needs to be approved by a second
> reviewer and that'll block the single-review-merge just as well).
>
> Antony
>
> On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux >>> > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> wrote:
>
> The proposed scheme by Paul doesn't seem reasonable to me. Core
> contributor A or committers needs to actively reach out to other
> core contributors: labeling is not enough IMO.
>
>
> On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca >>> > <mailto:jklymak at uvic.ca>> wrote:
>
>
>
>> On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com >>> >> <mailto:pmhobson at gmail.com>> wrote:
>>
>> I think this would be a good policy as well. Can I get some
>> clarification on the flow? The way I understand it:
>>
>> 1) Someone (committer, contributor, or first-timer) opens a
>> simple PR
>> 2) Committer A reviews it, adds a "single-review-merge" label,
>> then digitally walks away
>> 3) No less than two weeks later, Committer B sees the PR,
>> notices the label, opens it up, and merges without reviewing.
>
> If there is a Committer B, I think they should at least look at
> the PR to make sure it doesn?t have any hidden API changes, or
> introduce anything hostile.
>
> The point here is that getting the third person to look at a PR
> is proving quite difficult, and if the rest of the folks with
> the commit bit haven?t looked at a PR for a month, even after
> being warned, then silence indicates consent.
>
> Note that only folks with the commit bit can label PRs, so
> anyone flagging a PR like this is implicitly trusted to not be
> wreaking havoc, and not doing this for major changes. Since we
> all curate our own PRs, I rather expect that the PR contributor
> will often be the person who adds the flag. Whether we want to
> allow a self-merge at that point is up for debate, but if not,
> then folks need to get in the habit of looking at old flagged
> PRs and merging them.
>
> I think a huge problem we have is the LIFO default sort of the
> github PR queue, and that any PR not on the first page might as
> well be closed for all the attention it will get without
> constant nagging.
>
> Cheers, Jody
>
>> Does that capture a successful "single-review-merge"
lifecycle?
>> -paul
>>
>> On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux >>> >> <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com >>> >> >>> >> wrote:
>>
>> Hello,
>>
>> Overall, I think this is a good idea, but I would like
>> specifics on what "uncontroversial but uninteresting" PR
>> mean. IMO, that should exclude any PR with API changes.
>>
>> Cheers,
>> N
>>
>> On Tue, 15 Jan 2019 at 06:00, Antony Lee >>> >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> >>> wrote:
>>
>> Hi all,
>>
>> During the weekly dev call, I proposed to amend the PR
>> merge rules, following an initial comment on Github
>> [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].

>> There was general agreement among the devs present
>> (Tom, Hannah, Jody, and myself), so I'm putting it
>> here for discussion. The objective of this change is
>> to prevent "uncontroversial but uninteresting" PRs
>> from falling into oblivion, and try to decrease the
>> size of the open PR stack.
>>
>> The current rule is that a PR needs positive reviews
>> (from two committers, and excluding the author if a
>> committer) to be merged, except that doc-only PRs
>> (docstrings, rst) only needs a single positive review.
>>
>> I am proposing that, if a (non-doc) PR already has one
>> positive review, but no activity on that PR has
>> occurred for two weeks (exact time interval up to
>> bikeshedding) [Jody suggests: and the PR has 100% code
>> coverage], then a committer (either the first
>> reviewer, or the author if a committer) can suggest
>> that it be merged on the basis of that single review.
>> To do so, the "sponsor" should ping all developers
>> (@matplotlib/developers) on that issue indicating that
>> intent, and add a "single-review-merge" label on the
>> PR (so that these PRs can easily be found).
>> Committers are encouraged to review the PR to accept
>> and merge it or reject it or request changes on it;
>> but they can also just indicate that they consider the
>> PR sufficiently complex that a proper second review is
>> needed before merging, or request an extension, etc.
>> To do so they should still leave a "reject" review,
>> even if just saying "objecting to single-review
>> merged; anyone can dismiss after a second review".
>> However, if within another two weeks, no committer
>> voiced any objection (explicitly, i.e. by rejecting),
>> then the PR can indeed be merged on the basis of that
>> single review.
>>
>> To avoid overwhelming the system, any committer can
>> only "sponsor" a single PR at a time.
>>
>> Thoughts?
>>
>> Antony
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>>
Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>> Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org <mailto:
Matplotlib-devel at python.org>
>> Matplotlib-devel Info Page
>
> --
> Jody Klymak
> Jody M. Klymak - UVic Ocean Physics
>
>
>
>
>
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel at python.org <mailto:Matplotlib-devel at python.org>
> Matplotlib-devel Info Page
>
>
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel at python.org
> Matplotlib-devel Info Page
>

_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel at python.org
Matplotlib-devel Info Page

_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel at python.org
Matplotlib-devel Info Page

--
Thomas Caswell
tcaswell at gmail.com
_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel at python.org
Matplotlib-devel Info Page

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I think it is good remember that (as far as I know) everyone submitting PRs
and everyone reviewing them isn't paid and does so in their spare time;
therefore is no obligation for anyone to review anything on any particular
timescale. One thing that hasn't been discussed is how to increase the
reviewing capacity of the community, which I guess would involve working
out how to attract and retain more regular contributors.

re. the proposed changes, I'm +1 modulo objective criteria being agreed
upon. Personally I agree with Nelle's list, with the addition "has 100%
code coverage".

David

···

On Tue, 15 Jan 2019, 23:46 Nelle Varoquaux <nelle.varoquaux at gmail.com wrote:

For the way GitHub sorts pull requests, it is indeed a problem, but
there's a way to sort by "most recently updated." I sometimes use it to
make sure that I review recently updated pull request that don't appear on
the first page.

It seems to me that this "uncontroversial but uninteresting" rule is
currently not based on objective criteria. I'm personally not in favor of
removing two core contributors approval for anything that modifies the
API. We have had too many close calls on PR almost merged that had
backward incompatible changes: I realize that some core developers believe
that we are not moving fast enough, on a project with hundreds of thousands
of users, changes to the API should not be considered lightly.

Here's an attempt at better defining an "uncontroversial but
uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;
- Doesn't change the *public* API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;
- Is fully tested;
- All parameters are fully documented;
- Doesn't fix a release-critical bug;
- Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

To be honest, it also doesn't help that some people have 50+ pull requests
open (Antony? :p). It also doesn't help that some PR contain the same code
(13117, 13128) and are being hold off until the other one is merged (also,
why is 13117 being hold off for a PR that has been opened afterwards?).
IMO, if a PR can be merged, it should be merged. But we shouldn't make too
many exceptions to the two core contributors rules. It's easier to have two
core contributor review a pull request, than to try to fix API issues on
code that has been merged and released. Having two pairs of eyes on a PR is
also a good way to avoid having a bus factor of 1 on some areas of the
library.

On Tue, 15 Jan 2019 at 15:19, Thomas Caswell <tcaswell at gmail.com> wrote:

I think a distinction between "no one cares" and "no one has bandwidth"
needs to be made.

If you look at the 'pulse' page, we merging 100+ PRs a month (
Pulse · matplotlib/matplotlib · GitHub) so reviews are
happening, the issue is just that some are falling through the cracks.

Tom

On Tue, Jan 15, 2019 at 4:45 PM Antony Lee <antony.lee at institutoptique.fr> >> wrote:

Eric,
Neither the ttc font, nor the pdf/ps common code PRs actually touch any
"complex" point regarding fonts or pdf/ps. I have described the ttc font
in my previous message; the pdf/ps PR is really just, look, these two
classes share 80 lines worth of code that's literally copy-pasted, let's
just put that in a common parent class and inherit from it.
Conversely, one font-related PR for which I actually have low hopes of
getting properly reviewed (except on an "sure, I trust you" basis) is
textpath encoding by anntzer · Pull Request #12928 · matplotlib/matplotlib · GitHub, which actually
touches a rather complex point about font encodings (some of which I had to
clarify on the FreeType mailing list). (If anyone wants to have a look at
it, though... :p)
Antony

On Tue, Jan 15, 2019 at 10:36 PM Eric Firing <efiring at hawaii.edu> wrote:

Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable
time.

I'm fine with your proposed rule. It should help at least a little bit.

Eric

On 2019/01/15 9:11 AM, Antony Lee wrote:
> I'm obviously more aware of my own PRs, so here are a few I'd have
put
> up for single-review-merge (note that it's quite possible that they'd
> have attracted more attention and gotten merged faster under that
> system; that's also the goal...). Obviously other devs may think
about
> other PRs that could have benefitted from the same process.
>
> - Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support
for
> the ttc font format (requested since 2014) for png/svg output (that's
> provided basically for free by FreeType) but not for pdf/ps (that
would
> require more difficult changes). The entire PR comes down to:
> * adding "ttc" as an extension that should be treated like
"ttf"/"otf",
> * adding error handling to pdf/ps to signal these formats are not
> supported there,
> * tests.
> The PR sat open for 10 months before a first positive review
(because
> no one cares about fonts, I guess) and took another 3 months to
attract
> a second positive review.
>
> - Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a fairly
> trivial fix to fontList.json to make it reusable for Matplotlibs
> installed in different venvs, got a positive review in one day and
> waited another 2.5 months for a second positive review.
>
> - Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
> completely duplicated code between the pdf and ps backends, mostly
for
> maintainability's sake; it took 7.5 months (and 5 rebases due to
> conflicts) to get a first positive review and another 6 (and around
as
> many rebases) to get a second one.
>
> -----
>
> As for the specifics (as I see it):
> - Someone opens a PR, it gets a positive review, no negative review,
and
> no activity occurs for two weeks (significant activity -- excluding
> trivial chat on the thread).
> - Sponsor (first reviewer, or author if a committer) *pings* all devs
by
> mentioning @matplotlib/developers on the PR thread with the intent to
> single-review-merge, and labels the PR accordingly.
> - The PR can still be reviewed/merged/rejected by the normal review
> process. However, if no one explicitly opposes the merge within two
> weeks, anyone can merge it at that point (including by self-merge).
>
> I would not exclude all API changes from the process. For example,
>
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
> deprecates (and prepares for deletion) two parameters to imshow()
that
> have had no effect since 2006. Let's pretend for a second this
commit
> was a single independent PR (and not an example to showcase the
> parameter-deprecating decorator...); if it started being forgotten I
> would have proposed it for single-review-merge (again, note that if
> you're worried about the change, you don't need to reject the PR; you
> can just say, I think this API change needs to be approved by a
second
> reviewer and that'll block the single-review-merge just as well).
>
> Antony
>
> On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux >>>> > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> wrote:
>
> The proposed scheme by Paul doesn't seem reasonable to me. Core
> contributor A or committers needs to actively reach out to other
> core contributors: labeling is not enough IMO.
>
>
> On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca >>>> > <mailto:jklymak at uvic.ca>> wrote:
>
>
>
>> On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com >>>> >> <mailto:pmhobson at gmail.com>> wrote:
>>
>> I think this would be a good policy as well. Can I get some
>> clarification on the flow? The way I understand it:
>>
>> 1) Someone (committer, contributor, or first-timer) opens a
>> simple PR
>> 2) Committer A reviews it, adds a "single-review-merge"
label,
>> then digitally walks away
>> 3) No less than two weeks later, Committer B sees the PR,
>> notices the label, opens it up, and merges without reviewing.
>
> If there is a Committer B, I think they should at least look
at
> the PR to make sure it doesn?t have any hidden API changes, or
> introduce anything hostile.
>
> The point here is that getting the third person to look at a
PR
> is proving quite difficult, and if the rest of the folks with
> the commit bit haven?t looked at a PR for a month, even after
> being warned, then silence indicates consent.
>
> Note that only folks with the commit bit can label PRs, so
> anyone flagging a PR like this is implicitly trusted to not be
> wreaking havoc, and not doing this for major changes. Since
we
> all curate our own PRs, I rather expect that the PR
contributor
> will often be the person who adds the flag. Whether we want
to
> allow a self-merge at that point is up for debate, but if not,
> then folks need to get in the habit of looking at old flagged
> PRs and merging them.
>
> I think a huge problem we have is the LIFO default sort of the
> github PR queue, and that any PR not on the first page might
as
> well be closed for all the attention it will get without
> constant nagging.
>
> Cheers, Jody
>
>> Does that capture a successful "single-review-merge"
lifecycle?
>> -paul
>>
>> On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux >>>> >> <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com >>>> >> >>>> >> wrote:
>>
>> Hello,
>>
>> Overall, I think this is a good idea, but I would like
>> specifics on what "uncontroversial but uninteresting" PR
>> mean. IMO, that should exclude any PR with API changes.
>>
>> Cheers,
>> N
>>
>> On Tue, 15 Jan 2019 at 06:00, Antony Lee >>>> >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> >>>> wrote:
>>
>> Hi all,
>>
>> During the weekly dev call, I proposed to amend the
PR
>> merge rules, following an initial comment on Github
>> [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].

>> There was general agreement among the devs present
>> (Tom, Hannah, Jody, and myself), so I'm putting it
>> here for discussion. The objective of this change is
>> to prevent "uncontroversial but uninteresting" PRs
>> from falling into oblivion, and try to decrease the
>> size of the open PR stack.
>>
>> The current rule is that a PR needs positive reviews
>> (from two committers, and excluding the author if a
>> committer) to be merged, except that doc-only PRs
>> (docstrings, rst) only needs a single positive
review.
>>
>> I am proposing that, if a (non-doc) PR already has
one
>> positive review, but no activity on that PR has
>> occurred for two weeks (exact time interval up to
>> bikeshedding) [Jody suggests: and the PR has 100%
code
>> coverage], then a committer (either the first
>> reviewer, or the author if a committer) can suggest
>> that it be merged on the basis of that single
review.
>> To do so, the "sponsor" should ping all developers
>> (@matplotlib/developers) on that issue indicating
that
>> intent, and add a "single-review-merge" label on the
>> PR (so that these PRs can easily be found).
>> Committers are encouraged to review the PR to accept
>> and merge it or reject it or request changes on it;
>> but they can also just indicate that they consider
the
>> PR sufficiently complex that a proper second review
is
>> needed before merging, or request an extension, etc.
>> To do so they should still leave a "reject" review,
>> even if just saying "objecting to single-review
>> merged; anyone can dismiss after a second review".
>> However, if within another two weeks, no committer
>> voiced any objection (explicitly, i.e. by rejecting),
>> then the PR can indeed be merged on the basis of that
>> single review.
>>
>> To avoid overwhelming the system, any committer can
>> only "sponsor" a single PR at a time.
>>
>> Thoughts?
>>
>> Antony
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>>
Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>>
Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org <mailto:
Matplotlib-devel at python.org>
>> Matplotlib-devel Info Page
>
> --
> Jody Klymak
> Jody M. Klymak - UVic Ocean Physics
>
>
>
>
>
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel at python.org <mailto:Matplotlib-devel at python.org>
> Matplotlib-devel Info Page
>
>
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel at python.org
> Matplotlib-devel Info Page
>

_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel at python.org
Matplotlib-devel Info Page

_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel at python.org
Matplotlib-devel Info Page

--
Thomas Caswell
tcaswell at gmail.com
_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel at python.org
Matplotlib-devel Info Page

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Replying to Nelle's points first:

It seems to me that this "uncontroversial but uninteresting" rule is
currently not based on objective criteria. I'm personally not in favor of
removing two core contributors approval for anything that modifies the
API. We have had too many close calls on PR almost merged that had
backward incompatible changes: I realize that some core developers believe
that we are not moving fast enough, on a project with hundreds of thousands
of users, changes to the API should not be considered lightly.

To be clear (and even though it is probably common knowledge that I would
like to evolve the API faster), there is no "secret agenda" of using this
to sneak API breaks through the system.

Here's an attempt at better defining an "uncontroversial but
uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;

Sounds reasonable (with a reasonably flexible interpretation -- similarly
to the "no activity since two weeks, excluding trivial chat"), basically
"no other core dev expressed interest in reviewing it".

- Doesn't change the public API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;

I expect all changes of API to go through the normal route of deprecation
and API change note, which even the first reviewer should make sure are
present before sponsoring the PR for single-review-merge (as an aside, I
guess the first reviewer could even say, "approving, but I don't want to
take the responsibility for being the single reviewer"...). So now you
have a two week period where any other core dev passing by can just see
whether there is an API change note and make their own judgment, including
deciding to block the PR if necessary, based on that change note.
I guess it is reasonable to say "API deprecations or changes and new
functionality should be clearly documented" to help that "skim-through"
review.
As for *adding* functionality, I guess you would have rejected the ttc-font
PR on that premise? (Actually I now see that the additional functionality
was actually not documented :)) Note that this is not some obscure edge
case that no one cares about; it's a feature that has been requested for
years on the tracker.

- Is fully tested;

Also proposed by Jody and now by David, sounds good to me.

- All parameters are fully documented;

(sounds contradictory with "doesn't add a functionality"... if there is no
new functionality it's unlikely there's a new parameter)

- Doesn't fix a release-critical bug;

These tend to all be merged just before the next release is cut anyways
(review dynamics are a bit different in these periods), so I wouldn't worry
about it, but sure.

- Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

I don't actually think this is a good rule; the pdf/ps merge PR is +138
lines, -182 lines but as explained above the change is fairly trivial;
obviously I could have split it into smaller chunks but if anything that
would have made it harder to review.
Conversely (to use an example I have already raised elsewhere)
FIX: Ensuring both x and y attrs of LocationEvent are int by TarasKuzyo · Pull Request #11530 · matplotlib/matplotlib · GitHub (making sure that
LocationEvent.x and LocationEvent.y are integers (as they refer to pixel
locations) rather than floats) is 2 lines of changes in the codebase and 20
lines of test, was reviewed by 2.5 core devs (I left a comment in passing)
and we all missed that there was "problem" with it (it broke mplcursors and
some other pieces of code I have that assume that it is possible to
synthetize LocationEvents pointing to arbitrary places in the canvas).
(Not to derail this discussion into how to evaluate API breaks once
again... but I think these kinds of changes are much more insidious than,
say, removing a function, as the latter would just trigger an
AttributeError that is easily noticed and at worst you just go back to the
previous Matplotlib release, whereas the LocationEvent change was only
caught because it was covered by the mplcursors test suite; otherwise I'd
have been silently generating wrong results due to it...)

To be honest, it also doesn't help that some people have 50+ pull requests
open (Antony? :p).

I guess if the way to fix Matplotlib is to not contribute to Matplotlib
anymore, we have a bigger problem. In fact, I have some pretty big patches
fixing long-standing issues (e.g. for #8550 I have a pure-Python
reimplementation of the fontconfig font weight deduction algorithm,
translated from fontconfig's C implementation) that I don't even bother
turning into PRs, as I know they have no chance of being reviewed and
merged under the current system at least, because no one would care (see
also the bus-factor point below).

It also doesn't help that some PR contain the same code (13117, 13128) and
are being hold off until the other one is merged (also, why is 13117 being
hold off for a PR that has been opened afterwards?). IMO, if a PR can be
merged, it should be merged.

That's discussed in

(FTR I actually agreed on merging 13117 directly, but apparently that's an
API break...)

But we shouldn't make too many exceptions to the two core contributors
rules. It's easier to have two core contributor review a pull request, than
to try to fix API issues on code that has been merged and released. Having
two pairs of eyes on a PR is also a good way to avoid having a bus factor
of 1 on some areas of the library.

There are already huge and central chunks of the library (Agg internals,
PDF/PS) that have a bus factor close to zero. If anything, I hope that
this "drive-by review" system will encourage reviewers to start looking at
places they are less familiar with ("oh yes, I guess this change makes
sense" -- see Eric's reply above) and decrease that.

And then to David's (the code-coverage point is already covered above):

I think it is good remember that (as far as I know) everyone submitting PRs

and everyone reviewing them isn't paid and does so in their spare time;
therefore is no obligation for anyone to review anything on any particular
timescale. One thing that hasn't been discussed is how to increase the
reviewing capacity of the community, which I guess would involve working
out how to attract and retain more regular contributors.

Given the premises "no one is paid to review PRs" and "the reviewing
capacity is too small" (which I agree with), I think there are two
reasonable solutions:
- Make PRs easier to merge (this proposal),
- Increasing to number of core devs (your proposal, but it's not clear to
me whether this number can increase significantly in a short period of
time...).

Antony

···

On Wed, Jan 16, 2019 at 10:34 AM David Stansby <dstansby at gmail.com> wrote:

I think it is good remember that (as far as I know) everyone submitting
PRs and everyone reviewing them isn't paid and does so in their spare time;
therefore is no obligation for anyone to review anything on any particular
timescale. One thing that hasn't been discussed is how to increase the
reviewing capacity of the community, which I guess would involve working
out how to attract and retain more regular contributors.

re. the proposed changes, I'm +1 modulo objective criteria being agreed
upon. Personally I agree with Nelle's list, with the addition "has 100%
code coverage".

David

On Tue, 15 Jan 2019, 23:46 Nelle Varoquaux <nelle.varoquaux at gmail.com > wrote:

For the way GitHub sorts pull requests, it is indeed a problem, but
there's a way to sort by "most recently updated." I sometimes use it to
make sure that I review recently updated pull request that don't appear on
the first page.

It seems to me that this "uncontroversial but uninteresting" rule is
currently not based on objective criteria. I'm personally not in favor of
removing two core contributors approval for anything that modifies the
API. We have had too many close calls on PR almost merged that had
backward incompatible changes: I realize that some core developers believe
that we are not moving fast enough, on a project with hundreds of thousands
of users, changes to the API should not be considered lightly.

Here's an attempt at better defining an "uncontroversial but
uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;
- Doesn't change the *public* API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;
- Is fully tested;
- All parameters are fully documented;
- Doesn't fix a release-critical bug;
- Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

To be honest, it also doesn't help that some people have 50+ pull
requests open (Antony? :p). It also doesn't help that some PR contain the
same code (13117, 13128) and are being hold off until the other one is
merged (also, why is 13117 being hold off for a PR that has been opened
afterwards?). IMO, if a PR can be merged, it should be merged. But we
shouldn't make too many exceptions to the two core contributors rules. It's
easier to have two core contributor review a pull request, than to try to
fix API issues on code that has been merged and released. Having two pairs
of eyes on a PR is also a good way to avoid having a bus factor of 1 on
some areas of the library.

On Tue, 15 Jan 2019 at 15:19, Thomas Caswell <tcaswell at gmail.com> wrote:

I think a distinction between "no one cares" and "no one has bandwidth"
needs to be made.

If you look at the 'pulse' page, we merging 100+ PRs a month (
Pulse · matplotlib/matplotlib · GitHub) so reviews are
happening, the issue is just that some are falling through the cracks.

Tom

On Tue, Jan 15, 2019 at 4:45 PM Antony Lee < >>> antony.lee at institutoptique.fr> wrote:

Eric,
Neither the ttc font, nor the pdf/ps common code PRs actually touch any
"complex" point regarding fonts or pdf/ps. I have described the ttc font
in my previous message; the pdf/ps PR is really just, look, these two
classes share 80 lines worth of code that's literally copy-pasted, let's
just put that in a common parent class and inherit from it.
Conversely, one font-related PR for which I actually have low hopes of
getting properly reviewed (except on an "sure, I trust you" basis) is
textpath encoding by anntzer · Pull Request #12928 · matplotlib/matplotlib · GitHub, which actually
touches a rather complex point about font encodings (some of which I had to
clarify on the FreeType mailing list). (If anyone wants to have a look at
it, though... :p)
Antony

On Tue, Jan 15, 2019 at 10:36 PM Eric Firing <efiring at hawaii.edu> >>>> wrote:

Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable
time.

I'm fine with your proposed rule. It should help at least a little
bit.

Eric

On 2019/01/15 9:11 AM, Antony Lee wrote:
> I'm obviously more aware of my own PRs, so here are a few I'd have
put
> up for single-review-merge (note that it's quite possible that
they'd
> have attracted more attention and gotten merged faster under that
> system; that's also the goal...). Obviously other devs may think
about
> other PRs that could have benefitted from the same process.
>
> - Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support
for
> the ttc font format (requested since 2014) for png/svg output
(that's
> provided basically for free by FreeType) but not for pdf/ps (that
would
> require more difficult changes). The entire PR comes down to:
> * adding "ttc" as an extension that should be treated like
"ttf"/"otf",
> * adding error handling to pdf/ps to signal these formats are not
> supported there,
> * tests.
> The PR sat open for 10 months before a first positive review
(because
> no one cares about fonts, I guess) and took another 3 months to
attract
> a second positive review.
>
> - Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a fairly
> trivial fix to fontList.json to make it reusable for Matplotlibs
> installed in different venvs, got a positive review in one day and
> waited another 2.5 months for a second positive review.
>
> - Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
> completely duplicated code between the pdf and ps backends, mostly
for
> maintainability's sake; it took 7.5 months (and 5 rebases due to
> conflicts) to get a first positive review and another 6 (and around
as
> many rebases) to get a second one.
>
> -----
>
> As for the specifics (as I see it):
> - Someone opens a PR, it gets a positive review, no negative review,
and
> no activity occurs for two weeks (significant activity -- excluding
> trivial chat on the thread).
> - Sponsor (first reviewer, or author if a committer) *pings* all
devs by
> mentioning @matplotlib/developers on the PR thread with the intent
to
> single-review-merge, and labels the PR accordingly.
> - The PR can still be reviewed/merged/rejected by the normal review
> process. However, if no one explicitly opposes the merge within two
> weeks, anyone can merge it at that point (including by self-merge).
>
> I would not exclude all API changes from the process. For example,
>
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
> deprecates (and prepares for deletion) two parameters to imshow()
that
> have had no effect since 2006. Let's pretend for a second this
commit
> was a single independent PR (and not an example to showcase the
> parameter-deprecating decorator...); if it started being forgotten I
> would have proposed it for single-review-merge (again, note that if
> you're worried about the change, you don't need to reject the PR;
you
> can just say, I think this API change needs to be approved by a
second
> reviewer and that'll block the single-review-merge just as well).
>
> Antony
>
> On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux >>>>> > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> >>>>> wrote:
>
> The proposed scheme by Paul doesn't seem reasonable to me. Core
> contributor A or committers needs to actively reach out to other
> core contributors: labeling is not enough IMO.
>
>
> On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca >>>>> > <mailto:jklymak at uvic.ca>> wrote:
>
>
>
>> On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com >>>>> >> <mailto:pmhobson at gmail.com>> wrote:
>>
>> I think this would be a good policy as well. Can I get some
>> clarification on the flow? The way I understand it:
>>
>> 1) Someone (committer, contributor, or first-timer) opens a
>> simple PR
>> 2) Committer A reviews it, adds a "single-review-merge"
label,
>> then digitally walks away
>> 3) No less than two weeks later, Committer B sees the PR,
>> notices the label, opens it up, and merges without
reviewing.
>
> If there is a Committer B, I think they should at least look
at
> the PR to make sure it doesn?t have any hidden API changes,
or
> introduce anything hostile.
>
> The point here is that getting the third person to look at a
PR
> is proving quite difficult, and if the rest of the folks with
> the commit bit haven?t looked at a PR for a month, even after
> being warned, then silence indicates consent.
>
> Note that only folks with the commit bit can label PRs, so
> anyone flagging a PR like this is implicitly trusted to not
be
> wreaking havoc, and not doing this for major changes. Since
we
> all curate our own PRs, I rather expect that the PR
contributor
> will often be the person who adds the flag. Whether we want
to
> allow a self-merge at that point is up for debate, but if
not,
> then folks need to get in the habit of looking at old flagged
> PRs and merging them.
>
> I think a huge problem we have is the LIFO default sort of
the
> github PR queue, and that any PR not on the first page might
as
> well be closed for all the attention it will get without
> constant nagging.
>
> Cheers, Jody
>
>> Does that capture a successful "single-review-merge"
lifecycle?
>> -paul
>>
>> On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux >>>>> >> <nelle.varoquaux at gmail.com <mailto: >>>>> nelle.varoquaux at gmail.com>> >>>>> >> wrote:
>>
>> Hello,
>>
>> Overall, I think this is a good idea, but I would like
>> specifics on what "uncontroversial but uninteresting" PR
>> mean. IMO, that should exclude any PR with API changes.
>>
>> Cheers,
>> N
>>
>> On Tue, 15 Jan 2019 at 06:00, Antony Lee >>>>> >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> >>>>> wrote:
>>
>> Hi all,
>>
>> During the weekly dev call, I proposed to amend the
PR
>> merge rules, following an initial comment on Github
>> [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].

>> There was general agreement among the devs present
>> (Tom, Hannah, Jody, and myself), so I'm putting it
>> here for discussion. The objective of this change
is
>> to prevent "uncontroversial but uninteresting" PRs
>> from falling into oblivion, and try to decrease the
>> size of the open PR stack.
>>
>> The current rule is that a PR needs positive reviews
>> (from two committers, and excluding the author if a
>> committer) to be merged, except that doc-only PRs
>> (docstrings, rst) only needs a single positive
review.
>>
>> I am proposing that, if a (non-doc) PR already has
one
>> positive review, but no activity on that PR has
>> occurred for two weeks (exact time interval up to
>> bikeshedding) [Jody suggests: and the PR has 100%
code
>> coverage], then a committer (either the first
>> reviewer, or the author if a committer) can suggest
>> that it be merged on the basis of that single
review.
>> To do so, the "sponsor" should ping all developers
>> (@matplotlib/developers) on that issue indicating
that
>> intent, and add a "single-review-merge" label on the
>> PR (so that these PRs can easily be found).
>> Committers are encouraged to review the PR to accept
>> and merge it or reject it or request changes on it;
>> but they can also just indicate that they consider
the
>> PR sufficiently complex that a proper second review
is
>> needed before merging, or request an extension,
etc.
>> To do so they should still leave a "reject" review,
>> even if just saying "objecting to single-review
>> merged; anyone can dismiss after a second review".
>> However, if within another two weeks, no committer
>> voiced any objection (explicitly, i.e. by
rejecting),
>> then the PR can indeed be merged on the basis of
that
>> single review.
>>
>> To avoid overwhelming the system, any committer can
>> only "sponsor" a single PR at a time.
>>
>> Thoughts?
>>
>> Antony
>> _______________________________________________
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>>
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>> _______________________________________________
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>
> --
> Jody Klymak
> Jody M. Klymak - UVic Ocean Physics
>
>
>
>
>
> _______________________________________________
> Matplotlib-devel mailing list
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I want to push back strongly on the notion that "did not review --> does
not care". As as already been discussed above there are many other reasons
someone does not comment (for example "I _do_ care about this, but I {do
not have time, am too tired and cranky, ...} to properly review this now").

It seems to me that there are two classes of PRs that are getting grouped
together here: small PRs that just fall through the cracks and big PRs that
are hard to review, let's stay focused on the small PRs.

One habit related thing that may help is if we all bookmark:

https://github.com/matplotlib/matplotlib/pulls?q=is%3Apr+is%3Aopen+review%3Aapproved+sort%3Aupdated-desc

as where to start when we sit down to do some Matplotlib work. I would
also remind everyone that if you have a commit bit, then we trust you to
use it!

As we write down the list of things that need to be true for single-review
merging, it seems the effort to determine that a given PR checks (or does
not) all of the boxes is equal to the effort to just review the PR. This
make me think that the biggest benefit of this change would be to get more
eyes on PRs than any policy change.

To a fair degree this comes down to a project management / resource
allocation problem (which are hard even in situations where everyone is
paid!)

Tom

···

On Wed, Jan 16, 2019 at 6:11 AM Antony Lee <antony.lee at institutoptique.fr> wrote:

Replying to Nelle's points first:

It seems to me that this "uncontroversial but uninteresting" rule is
currently not based on objective criteria. I'm personally not in favor of
removing two core contributors approval for anything that modifies the
API. We have had too many close calls on PR almost merged that had
backward incompatible changes: I realize that some core developers believe
that we are not moving fast enough, on a project with hundreds of thousands
of users, changes to the API should not be considered lightly.

To be clear (and even though it is probably common knowledge that I would
like to evolve the API faster), there is no "secret agenda" of using this
to sneak API breaks through the system.

Here's an attempt at better defining an "uncontroversial but
uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;

Sounds reasonable (with a reasonably flexible interpretation -- similarly
to the "no activity since two weeks, excluding trivial chat"), basically
"no other core dev expressed interest in reviewing it".

- Doesn't change the public API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;

I expect all changes of API to go through the normal route of deprecation
and API change note, which even the first reviewer should make sure are
present before sponsoring the PR for single-review-merge (as an aside, I
guess the first reviewer could even say, "approving, but I don't want to
take the responsibility for being the single reviewer"...). So now you
have a two week period where any other core dev passing by can just see
whether there is an API change note and make their own judgment, including
deciding to block the PR if necessary, based on that change note.
I guess it is reasonable to say "API deprecations or changes and new
functionality should be clearly documented" to help that "skim-through"
review.
As for *adding* functionality, I guess you would have rejected the
ttc-font PR on that premise? (Actually I now see that the additional
functionality was actually not documented :)) Note that this is not some
obscure edge case that no one cares about; it's a feature that has been
requested for years on the tracker.

- Is fully tested;

Also proposed by Jody and now by David, sounds good to me.

- All parameters are fully documented;

(sounds contradictory with "doesn't add a functionality"... if there is no
new functionality it's unlikely there's a new parameter)

- Doesn't fix a release-critical bug;

These tend to all be merged just before the next release is cut anyways
(review dynamics are a bit different in these periods), so I wouldn't worry
about it, but sure.

- Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

I don't actually think this is a good rule; the pdf/ps merge PR is +138
lines, -182 lines but as explained above the change is fairly trivial;
obviously I could have split it into smaller chunks but if anything that
would have made it harder to review.
Conversely (to use an example I have already raised elsewhere)
FIX: Ensuring both x and y attrs of LocationEvent are int by TarasKuzyo · Pull Request #11530 · matplotlib/matplotlib · GitHub (making sure that
LocationEvent.x and LocationEvent.y are integers (as they refer to pixel
locations) rather than floats) is 2 lines of changes in the codebase and 20
lines of test, was reviewed by 2.5 core devs (I left a comment in passing)
and we all missed that there was "problem" with it (it broke mplcursors and
some other pieces of code I have that assume that it is possible to
synthetize LocationEvents pointing to arbitrary places in the canvas).
(Not to derail this discussion into how to evaluate API breaks once
again... but I think these kinds of changes are much more insidious than,
say, removing a function, as the latter would just trigger an
AttributeError that is easily noticed and at worst you just go back to the
previous Matplotlib release, whereas the LocationEvent change was only
caught because it was covered by the mplcursors test suite; otherwise I'd
have been silently generating wrong results due to it...)

To be honest, it also doesn't help that some people have 50+ pull
requests open (Antony? :p).

I guess if the way to fix Matplotlib is to not contribute to Matplotlib
anymore, we have a bigger problem. In fact, I have some pretty big patches
fixing long-standing issues (e.g. for #8550 I have a pure-Python
reimplementation of the fontconfig font weight deduction algorithm,
translated from fontconfig's C implementation) that I don't even bother
turning into PRs, as I know they have no chance of being reviewed and
merged under the current system at least, because no one would care (see
also the bus-factor point below).

It also doesn't help that some PR contain the same code (13117, 13128)
and are being hold off until the other one is merged (also, why is 13117
being hold off for a PR that has been opened afterwards?). IMO, if a PR can
be merged, it should be merged.

That's discussed in
Cleanup matplotlib.use by timhoffm · Pull Request #13117 · matplotlib/matplotlib · GitHub
(FTR I actually agreed on merging 13117 directly, but apparently that's an
API break...)

But we shouldn't make too many exceptions to the two core contributors
rules. It's easier to have two core contributor review a pull request, than
to try to fix API issues on code that has been merged and released. Having
two pairs of eyes on a PR is also a good way to avoid having a bus factor
of 1 on some areas of the library.

There are already huge and central chunks of the library (Agg internals,
PDF/PS) that have a bus factor close to zero. If anything, I hope that
this "drive-by review" system will encourage reviewers to start looking at
places they are less familiar with ("oh yes, I guess this change makes
sense" -- see Eric's reply above) and decrease that.

And then to David's (the code-coverage point is already covered above):

I think it is good remember that (as far as I know) everyone submitting

PRs and everyone reviewing them isn't paid and does so in their spare time;
therefore is no obligation for anyone to review anything on any particular
timescale. One thing that hasn't been discussed is how to increase the
reviewing capacity of the community, which I guess would involve working
out how to attract and retain more regular contributors.

Given the premises "no one is paid to review PRs" and "the reviewing
capacity is too small" (which I agree with), I think there are two
reasonable solutions:
- Make PRs easier to merge (this proposal),
- Increasing to number of core devs (your proposal, but it's not clear to
me whether this number can increase significantly in a short period of
time...).

Antony

On Wed, Jan 16, 2019 at 10:34 AM David Stansby <dstansby at gmail.com> wrote:

I think it is good remember that (as far as I know) everyone submitting
PRs and everyone reviewing them isn't paid and does so in their spare time;
therefore is no obligation for anyone to review anything on any particular
timescale. One thing that hasn't been discussed is how to increase the
reviewing capacity of the community, which I guess would involve working
out how to attract and retain more regular contributors.

re. the proposed changes, I'm +1 modulo objective criteria being agreed
upon. Personally I agree with Nelle's list, with the addition "has 100%
code coverage".

David

On Tue, 15 Jan 2019, 23:46 Nelle Varoquaux <nelle.varoquaux at gmail.com >> wrote:

For the way GitHub sorts pull requests, it is indeed a problem, but
there's a way to sort by "most recently updated." I sometimes use it to
make sure that I review recently updated pull request that don't appear on
the first page.

It seems to me that this "uncontroversial but uninteresting" rule is
currently not based on objective criteria. I'm personally not in favor of
removing two core contributors approval for anything that modifies the
API. We have had too many close calls on PR almost merged that had
backward incompatible changes: I realize that some core developers believe
that we are not moving fast enough, on a project with hundreds of thousands
of users, changes to the API should not be considered lightly.

Here's an attempt at better defining an "uncontroversial but
uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;
- Doesn't change the *public* API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;
- Is fully tested;
- All parameters are fully documented;
- Doesn't fix a release-critical bug;
- Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

To be honest, it also doesn't help that some people have 50+ pull
requests open (Antony? :p). It also doesn't help that some PR contain the
same code (13117, 13128) and are being hold off until the other one is
merged (also, why is 13117 being hold off for a PR that has been opened
afterwards?). IMO, if a PR can be merged, it should be merged. But we
shouldn't make too many exceptions to the two core contributors rules. It's
easier to have two core contributor review a pull request, than to try to
fix API issues on code that has been merged and released. Having two pairs
of eyes on a PR is also a good way to avoid having a bus factor of 1 on
some areas of the library.

On Tue, 15 Jan 2019 at 15:19, Thomas Caswell <tcaswell at gmail.com> wrote:

I think a distinction between "no one cares" and "no one has bandwidth"
needs to be made.

If you look at the 'pulse' page, we merging 100+ PRs a month (
Pulse · matplotlib/matplotlib · GitHub) so reviews are
happening, the issue is just that some are falling through the cracks.

Tom

On Tue, Jan 15, 2019 at 4:45 PM Antony Lee < >>>> antony.lee at institutoptique.fr> wrote:

Eric,
Neither the ttc font, nor the pdf/ps common code PRs actually touch
any "complex" point regarding fonts or pdf/ps. I have described the ttc
font in my previous message; the pdf/ps PR is really just, look, these two
classes share 80 lines worth of code that's literally copy-pasted, let's
just put that in a common parent class and inherit from it.
Conversely, one font-related PR for which I actually have low hopes of
getting properly reviewed (except on an "sure, I trust you" basis) is
textpath encoding by anntzer · Pull Request #12928 · matplotlib/matplotlib · GitHub, which actually
touches a rather complex point about font encodings (some of which I had to
clarify on the FreeType mailing list). (If anyone wants to have a look at
it, though... :p)
Antony

On Tue, Jan 15, 2019 at 10:36 PM Eric Firing <efiring at hawaii.edu> >>>>> wrote:

Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable
time.

I'm fine with your proposed rule. It should help at least a little
bit.

Eric

On 2019/01/15 9:11 AM, Antony Lee wrote:
> I'm obviously more aware of my own PRs, so here are a few I'd have
put
> up for single-review-merge (note that it's quite possible that
they'd
> have attracted more attention and gotten merged faster under that
> system; that's also the goal...). Obviously other devs may think
about
> other PRs that could have benefitted from the same process.
>
> - Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support
for
> the ttc font format (requested since 2014) for png/svg output
(that's
> provided basically for free by FreeType) but not for pdf/ps (that
would
> require more difficult changes). The entire PR comes down to:
> * adding "ttc" as an extension that should be treated like
"ttf"/"otf",
> * adding error handling to pdf/ps to signal these formats are
not
> supported there,
> * tests.
> The PR sat open for 10 months before a first positive review
(because
> no one cares about fonts, I guess) and took another 3 months to
attract
> a second positive review.
>
> - Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a
fairly
> trivial fix to fontList.json to make it reusable for Matplotlibs
> installed in different venvs, got a positive review in one day and
> waited another 2.5 months for a second positive review.
>
> - Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
> completely duplicated code between the pdf and ps backends, mostly
for
> maintainability's sake; it took 7.5 months (and 5 rebases due to
> conflicts) to get a first positive review and another 6 (and around
as
> many rebases) to get a second one.
>
> -----
>
> As for the specifics (as I see it):
> - Someone opens a PR, it gets a positive review, no negative
review, and
> no activity occurs for two weeks (significant activity -- excluding
> trivial chat on the thread).
> - Sponsor (first reviewer, or author if a committer) *pings* all
devs by
> mentioning @matplotlib/developers on the PR thread with the intent
to
> single-review-merge, and labels the PR accordingly.
> - The PR can still be reviewed/merged/rejected by the normal review
> process. However, if no one explicitly opposes the merge within
two
> weeks, anyone can merge it at that point (including by self-merge).
>
> I would not exclude all API changes from the process. For example,
>
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
> deprecates (and prepares for deletion) two parameters to imshow()
that
> have had no effect since 2006. Let's pretend for a second this
commit
> was a single independent PR (and not an example to showcase the
> parameter-deprecating decorator...); if it started being forgotten
I
> would have proposed it for single-review-merge (again, note that if
> you're worried about the change, you don't need to reject the PR;
you
> can just say, I think this API change needs to be approved by a
second
> reviewer and that'll block the single-review-merge just as well).
>
> Antony
>
> On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux >>>>>> > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> >>>>>> wrote:
>
> The proposed scheme by Paul doesn't seem reasonable to me. Core
> contributor A or committers needs to actively reach out to other
> core contributors: labeling is not enough IMO.
>
>
> On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca >>>>>> > <mailto:jklymak at uvic.ca>> wrote:
>
>
>
>> On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com >>>>>> >> <mailto:pmhobson at gmail.com>> wrote:
>>
>> I think this would be a good policy as well. Can I get some
>> clarification on the flow? The way I understand it:
>>
>> 1) Someone (committer, contributor, or first-timer) opens a
>> simple PR
>> 2) Committer A reviews it, adds a "single-review-merge"
label,
>> then digitally walks away
>> 3) No less than two weeks later, Committer B sees the PR,
>> notices the label, opens it up, and merges without
reviewing.
>
> If there is a Committer B, I think they should at least
look at
> the PR to make sure it doesn?t have any hidden API changes,
or
> introduce anything hostile.
>
> The point here is that getting the third person to look at
a PR
> is proving quite difficult, and if the rest of the folks
with
> the commit bit haven?t looked at a PR for a month, even
after
> being warned, then silence indicates consent.
>
> Note that only folks with the commit bit can label PRs, so
> anyone flagging a PR like this is implicitly trusted to not
be
> wreaking havoc, and not doing this for major changes.
Since we
> all curate our own PRs, I rather expect that the PR
contributor
> will often be the person who adds the flag. Whether we
want to
> allow a self-merge at that point is up for debate, but if
not,
> then folks need to get in the habit of looking at old
flagged
> PRs and merging them.
>
> I think a huge problem we have is the LIFO default sort of
the
> github PR queue, and that any PR not on the first page
might as
> well be closed for all the attention it will get without
> constant nagging.
>
> Cheers, Jody
>
>> Does that capture a successful "single-review-merge"
lifecycle?
>> -paul
>>
>> On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux >>>>>> >> <nelle.varoquaux at gmail.com <mailto: >>>>>> nelle.varoquaux at gmail.com>> >>>>>> >> wrote:
>>
>> Hello,
>>
>> Overall, I think this is a good idea, but I would like
>> specifics on what "uncontroversial but uninteresting"
PR
>> mean. IMO, that should exclude any PR with API changes.
>>
>> Cheers,
>> N
>>
>> On Tue, 15 Jan 2019 at 06:00, Antony Lee >>>>>> >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> >>>>>> wrote:
>>
>> Hi all,
>>
>> During the weekly dev call, I proposed to amend
the PR
>> merge rules, following an initial comment on Github
>> [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].

>> There was general agreement among the devs present
>> (Tom, Hannah, Jody, and myself), so I'm putting it
>> here for discussion. The objective of this change
is
>> to prevent "uncontroversial but uninteresting" PRs
>> from falling into oblivion, and try to decrease the
>> size of the open PR stack.
>>
>> The current rule is that a PR needs positive
reviews
>> (from two committers, and excluding the author if a
>> committer) to be merged, except that doc-only PRs
>> (docstrings, rst) only needs a single positive
review.
>>
>> I am proposing that, if a (non-doc) PR already has
one
>> positive review, but no activity on that PR has
>> occurred for two weeks (exact time interval up to
>> bikeshedding) [Jody suggests: and the PR has 100%
code
>> coverage], then a committer (either the first
>> reviewer, or the author if a committer) can suggest
>> that it be merged on the basis of that single
review.
>> To do so, the "sponsor" should ping all developers
>> (@matplotlib/developers) on that issue indicating
that
>> intent, and add a "single-review-merge" label on
the
>> PR (so that these PRs can easily be found).
>> Committers are encouraged to review the PR to
accept
>> and merge it or reject it or request changes on it;
>> but they can also just indicate that they consider
the
>> PR sufficiently complex that a proper second
review is
>> needed before merging, or request an extension,
etc.
>> To do so they should still leave a "reject" review,
>> even if just saying "objecting to single-review
>> merged; anyone can dismiss after a second review".
>> However, if within another two weeks, no committer
>> voiced any objection (explicitly, i.e. by
rejecting),
>> then the PR can indeed be merged on the basis of
that
>> single review.
>>
>> To avoid overwhelming the system, any committer can
>> only "sponsor" a single PR at a time.
>>
>> Thoughts?
>>
>> Antony
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>>
Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
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>> <mailto:Matplotlib-devel at python.org>
>>
Matplotlib-devel Info Page
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org <mailto:
Matplotlib-devel at python.org>
>> Matplotlib-devel Info Page
>
> --
> Jody Klymak
> Jody M. Klymak - UVic Ocean Physics
>
>
>
>
>
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel at python.org <mailto:Matplotlib-devel at python.org
>
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>
>
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>

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There is a mathematical necessity here; if you have the commit bit and submit 50 PRs a month, you need to review 100 PRs a month, and merge or close 50 of those PRs a month. If all the folks with commit bit do this, then obviously PRs will pile up.

Cheers, Jody

···

On Jan 16, 2019, at 6:32 AM, Thomas Caswell <tcaswell at gmail.com> wrote:

I want to push back strongly on the notion that "did not review --> does not care". As as already been discussed above there are many other reasons someone does not comment (for example "I _do_ care about this, but I {do not have time, am too tired and cranky, ...} to properly review this now").

It seems to me that there are two classes of PRs that are getting grouped together here: small PRs that just fall through the cracks and big PRs that are hard to review, let's stay focused on the small PRs.

One habit related thing that may help is if we all bookmark:

Pull requests · matplotlib/matplotlib · GitHub

as where to start when we sit down to do some Matplotlib work. I would also remind everyone that if you have a commit bit, then we trust you to use it!

As we write down the list of things that need to be true for single-review merging, it seems the effort to determine that a given PR checks (or does not) all of the boxes is equal to the effort to just review the PR. This make me think that the biggest benefit of this change would be to get more eyes on PRs than any policy change.

To a fair degree this comes down to a project management / resource allocation problem (which are hard even in situations where everyone is paid!)

Tom

On Wed, Jan 16, 2019 at 6:11 AM Antony Lee <antony.lee at institutoptique.fr <mailto:antony.lee at institutoptique.fr>> wrote:
Replying to Nelle's points first:

It seems to me that this "uncontroversial but uninteresting" rule is currently not based on objective criteria. I'm personally not in favor of removing two core contributors approval for anything that modifies the API. We have had too many close calls on PR almost merged that had backward incompatible changes: I realize that some core developers believe that we are not moving fast enough, on a project with hundreds of thousands of users, changes to the API should not be considered lightly.

To be clear (and even though it is probably common knowledge that I would like to evolve the API faster), there is no "secret agenda" of using this to sneak API breaks through the system.

Here's an attempt at better defining an "uncontroversial but uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;

Sounds reasonable (with a reasonably flexible interpretation -- similarly to the "no activity since two weeks, excluding trivial chat"), basically "no other core dev expressed interest in reviewing it".

- Doesn't change the public API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;

I expect all changes of API to go through the normal route of deprecation and API change note, which even the first reviewer should make sure are present before sponsoring the PR for single-review-merge (as an aside, I guess the first reviewer could even say, "approving, but I don't want to take the responsibility for being the single reviewer"...). So now you have a two week period where any other core dev passing by can just see whether there is an API change note and make their own judgment, including deciding to block the PR if necessary, based on that change note.
I guess it is reasonable to say "API deprecations or changes and new functionality should be clearly documented" to help that "skim-through" review.
As for *adding* functionality, I guess you would have rejected the ttc-font PR on that premise? (Actually I now see that the additional functionality was actually not documented :)) Note that this is not some obscure edge case that no one cares about; it's a feature that has been requested for years on the tracker.

- Is fully tested;

Also proposed by Jody and now by David, sounds good to me.

- All parameters are fully documented;

(sounds contradictory with "doesn't add a functionality"... if there is no new functionality it's unlikely there's a new parameter)

- Doesn't fix a release-critical bug;

These tend to all be merged just before the next release is cut anyways (review dynamics are a bit different in these periods), so I wouldn't worry about it, but sure.

- Is less than XX lines of code. (Long PR are harder to review, and thus the likelihood of one core dev not noticing a problem is higher). Threshold needs to be defined.

I don't actually think this is a good rule; the pdf/ps merge PR is +138 lines, -182 lines but as explained above the change is fairly trivial; obviously I could have split it into smaller chunks but if anything that would have made it harder to review.
Conversely (to use an example I have already raised elsewhere) FIX: Ensuring both x and y attrs of LocationEvent are int by TarasKuzyo · Pull Request #11530 · matplotlib/matplotlib · GitHub (making sure that LocationEvent.x and LocationEvent.y are integers (as they refer to pixel locations) rather than floats) is 2 lines of changes in the codebase and 20 lines of test, was reviewed by 2.5 core devs (I left a comment in passing) and we all missed that there was "problem" with it (it broke mplcursors and some other pieces of code I have that assume that it is possible to synthetize LocationEvents pointing to arbitrary places in the canvas). (Not to derail this discussion into how to evaluate API breaks once again... but I think these kinds of changes are much more insidious than, say, removing a function, as the latter would just trigger an AttributeError that is easily noticed and at worst you just go back to the previous Matplotlib release, whereas the LocationEvent change was only caught because it was covered by the mplcursors test suite; otherwise I'd have been silently generating wrong results due to it...)

To be honest, it also doesn't help that some people have 50+ pull requests open (Antony? :p).

I guess if the way to fix Matplotlib is to not contribute to Matplotlib anymore, we have a bigger problem. In fact, I have some pretty big patches fixing long-standing issues (e.g. for #8550 I have a pure-Python reimplementation of the fontconfig font weight deduction algorithm, translated from fontconfig's C implementation) that I don't even bother turning into PRs, as I know they have no chance of being reviewed and merged under the current system at least, because no one would care (see also the bus-factor point below).

It also doesn't help that some PR contain the same code (13117, 13128) and are being hold off until the other one is merged (also, why is 13117 being hold off for a PR that has been opened afterwards?). IMO, if a PR can be merged, it should be merged.

That's discussed in Cleanup matplotlib.use by timhoffm · Pull Request #13117 · matplotlib/matplotlib · GitHub (FTR I actually agreed on merging 13117 directly, but apparently that's an API break...)

But we shouldn't make too many exceptions to the two core contributors rules. It's easier to have two core contributor review a pull request, than to try to fix API issues on code that has been merged and released. Having two pairs of eyes on a PR is also a good way to avoid having a bus factor of 1 on some areas of the library.

There are already huge and central chunks of the library (Agg internals, PDF/PS) that have a bus factor close to zero. If anything, I hope that this "drive-by review" system will encourage reviewers to start looking at places they are less familiar with ("oh yes, I guess this change makes sense" -- see Eric's reply above) and decrease that.

And then to David's (the code-coverage point is already covered above):

I think it is good remember that (as far as I know) everyone submitting PRs and everyone reviewing them isn't paid and does so in their spare time; therefore is no obligation for anyone to review anything on any particular timescale. One thing that hasn't been discussed is how to increase the reviewing capacity of the community, which I guess would involve working out how to attract and retain more regular contributors.

Given the premises "no one is paid to review PRs" and "the reviewing capacity is too small" (which I agree with), I think there are two reasonable solutions:
- Make PRs easier to merge (this proposal),
- Increasing to number of core devs (your proposal, but it's not clear to me whether this number can increase significantly in a short period of time...).

Antony

On Wed, Jan 16, 2019 at 10:34 AM David Stansby <dstansby at gmail.com <mailto:dstansby at gmail.com>> wrote:
I think it is good remember that (as far as I know) everyone submitting PRs and everyone reviewing them isn't paid and does so in their spare time; therefore is no obligation for anyone to review anything on any particular timescale. One thing that hasn't been discussed is how to increase the reviewing capacity of the community, which I guess would involve working out how to attract and retain more regular contributors.

re. the proposed changes, I'm +1 modulo objective criteria being agreed upon. Personally I agree with Nelle's list, with the addition "has 100% code coverage".

David

On Tue, 15 Jan 2019, 23:46 Nelle Varoquaux <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com> wrote:
For the way GitHub sorts pull requests, it is indeed a problem, but there's a way to sort by "most recently updated." I sometimes use it to make sure that I review recently updated pull request that don't appear on the first page.

It seems to me that this "uncontroversial but uninteresting" rule is currently not based on objective criteria. I'm personally not in favor of removing two core contributors approval for anything that modifies the API. We have had too many close calls on PR almost merged that had backward incompatible changes: I realize that some core developers believe that we are not moving fast enough, on a project with hundreds of thousands of users, changes to the API should not be considered lightly.

Here's an attempt at better defining an "uncontroversial but uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;
- Doesn't change the public API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;
- Is fully tested;
- All parameters are fully documented;
- Doesn't fix a release-critical bug;
- Is less than XX lines of code. (Long PR are harder to review, and thus the likelihood of one core dev not noticing a problem is higher). Threshold needs to be defined.

To be honest, it also doesn't help that some people have 50+ pull requests open (Antony? :p). It also doesn't help that some PR contain the same code (13117, 13128) and are being hold off until the other one is merged (also, why is 13117 being hold off for a PR that has been opened afterwards?). IMO, if a PR can be merged, it should be merged. But we shouldn't make too many exceptions to the two core contributors rules. It's easier to have two core contributor review a pull request, than to try to fix API issues on code that has been merged and released. Having two pairs of eyes on a PR is also a good way to avoid having a bus factor of 1 on some areas of the library.

On Tue, 15 Jan 2019 at 15:19, Thomas Caswell <tcaswell at gmail.com <mailto:tcaswell at gmail.com>> wrote:
I think a distinction between "no one cares" and "no one has bandwidth" needs to be made.

If you look at the 'pulse' page, we merging 100+ PRs a month (Pulse · matplotlib/matplotlib · GitHub) so reviews are happening, the issue is just that some are falling through the cracks.

Tom

On Tue, Jan 15, 2019 at 4:45 PM Antony Lee <antony.lee at institutoptique.fr <mailto:antony.lee at institutoptique.fr>> wrote:
Eric,
Neither the ttc font, nor the pdf/ps common code PRs actually touch any "complex" point regarding fonts or pdf/ps. I have described the ttc font in my previous message; the pdf/ps PR is really just, look, these two classes share 80 lines worth of code that's literally copy-pasted, let's just put that in a common parent class and inherit from it.
Conversely, one font-related PR for which I actually have low hopes of getting properly reviewed (except on an "sure, I trust you" basis) is textpath encoding by anntzer · Pull Request #12928 · matplotlib/matplotlib · GitHub, which actually touches a rather complex point about font encodings (some of which I had to clarify on the FreeType mailing list). (If anyone wants to have a look at it, though... :p)
Antony

On Tue, Jan 15, 2019 at 10:36 PM Eric Firing <efiring at hawaii.edu <mailto:efiring at hawaii.edu>> wrote:
Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable time.

I'm fine with your proposed rule. It should help at least a little bit.

Eric

On 2019/01/15 9:11 AM, Antony Lee wrote:
> I'm obviously more aware of my own PRs, so here are a few I'd have put
> up for single-review-merge (note that it's quite possible that they'd
> have attracted more attention and gotten merged faster under that
> system; that's also the goal...). Obviously other devs may think about
> other PRs that could have benefitted from the same process.
>
> - Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support for
> the ttc font format (requested since 2014) for png/svg output (that's
> provided basically for free by FreeType) but not for pdf/ps (that would
> require more difficult changes). The entire PR comes down to:
> * adding "ttc" as an extension that should be treated like "ttf"/"otf",
> * adding error handling to pdf/ps to signal these formats are not
> supported there,
> * tests.
> The PR sat open for 10 months before a first positive review (because
> no one cares about fonts, I guess) and took another 3 months to attract
> a second positive review.
>
> - Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a fairly
> trivial fix to fontList.json to make it reusable for Matplotlibs
> installed in different venvs, got a positive review in one day and
> waited another 2.5 months for a second positive review.
>
> - Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
> completely duplicated code between the pdf and ps backends, mostly for
> maintainability's sake; it took 7.5 months (and 5 rebases due to
> conflicts) to get a first positive review and another 6 (and around as
> many rebases) to get a second one.
>
> -----
>
> As for the specifics (as I see it):
> - Someone opens a PR, it gets a positive review, no negative review, and
> no activity occurs for two weeks (significant activity -- excluding
> trivial chat on the thread).
> - Sponsor (first reviewer, or author if a committer) *pings* all devs by
> mentioning @matplotlib/developers on the PR thread with the intent to
> single-review-merge, and labels the PR accordingly.
> - The PR can still be reviewed/merged/rejected by the normal review
> process. However, if no one explicitly opposes the merge within two
> weeks, anyone can merge it at that point (including by self-merge).
>
> I would not exclude all API changes from the process. For example,
> https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
> deprecates (and prepares for deletion) two parameters to imshow() that
> have had no effect since 2006. Let's pretend for a second this commit
> was a single independent PR (and not an example to showcase the
> parameter-deprecating decorator...); if it started being forgotten I
> would have proposed it for single-review-merge (again, note that if
> you're worried about the change, you don't need to reject the PR; you
> can just say, I think this API change needs to be approved by a second
> reviewer and that'll block the single-review-merge just as well).
>
> Antony
>
> On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux > > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com> <mailto:nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>>> wrote:
>
> The proposed scheme by Paul doesn't seem reasonable to me. Core
> contributor A or committers needs to actively reach out to other
> core contributors: labeling is not enough IMO.
>
>
> On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca <mailto:jklymak at uvic.ca> > > <mailto:jklymak at uvic.ca <mailto:jklymak at uvic.ca>>> wrote:
>
>
>
>> On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com <mailto:pmhobson at gmail.com> > >> <mailto:pmhobson at gmail.com <mailto:pmhobson at gmail.com>>> wrote:
>>
>> I think this would be a good policy as well. Can I get some
>> clarification on the flow? The way I understand it:
>>
>> 1) Someone (committer, contributor, or first-timer) opens a
>> simple PR
>> 2) Committer A reviews it, adds a "single-review-merge" label,
>> then digitally walks away
>> 3) No less than two weeks later, Committer B sees the PR,
>> notices the label, opens it up, and merges without reviewing.
>
> If there is a Committer B, I think they should at least look at
> the PR to make sure it doesn?t have any hidden API changes, or
> introduce anything hostile.
>
> The point here is that getting the third person to look at a PR
> is proving quite difficult, and if the rest of the folks with
> the commit bit haven?t looked at a PR for a month, even after
> being warned, then silence indicates consent.
>
> Note that only folks with the commit bit can label PRs, so
> anyone flagging a PR like this is implicitly trusted to not be
> wreaking havoc, and not doing this for major changes. Since we
> all curate our own PRs, I rather expect that the PR contributor
> will often be the person who adds the flag. Whether we want to
> allow a self-merge at that point is up for debate, but if not,
> then folks need to get in the habit of looking at old flagged
> PRs and merging them.
>
> I think a huge problem we have is the LIFO default sort of the
> github PR queue, and that any PR not on the first page might as
> well be closed for all the attention it will get without
> constant nagging.
>
> Cheers, Jody
>
>> Does that capture a successful "single-review-merge" lifecycle?
>> -paul
>>
>> On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux > >> <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com> <mailto:nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>>> > >> wrote:
>>
>> Hello,
>>
>> Overall, I think this is a good idea, but I would like
>> specifics on what "uncontroversial but uninteresting" PR
>> mean. IMO, that should exclude any PR with API changes.
>>
>> Cheers,
>> N
>>
>> On Tue, 15 Jan 2019 at 06:00, Antony Lee > >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com> <mailto:anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>>> wrote:
>>
>> Hi all,
>>
>> During the weekly dev call, I proposed to amend the PR
>> merge rules, following an initial comment on Github
>> [Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].
>> There was general agreement among the devs present
>> (Tom, Hannah, Jody, and myself), so I'm putting it
>> here for discussion. The objective of this change is
>> to prevent "uncontroversial but uninteresting" PRs
>> from falling into oblivion, and try to decrease the
>> size of the open PR stack.
>>
>> The current rule is that a PR needs positive reviews
>> (from two committers, and excluding the author if a
>> committer) to be merged, except that doc-only PRs
>> (docstrings, rst) only needs a single positive review.
>>
>> I am proposing that, if a (non-doc) PR already has one
>> positive review, but no activity on that PR has
>> occurred for two weeks (exact time interval up to
>> bikeshedding) [Jody suggests: and the PR has 100% code
>> coverage], then a committer (either the first
>> reviewer, or the author if a committer) can suggest
>> that it be merged on the basis of that single review.
>> To do so, the "sponsor" should ping all developers
>> (@matplotlib/developers) on that issue indicating that
>> intent, and add a "single-review-merge" label on the
>> PR (so that these PRs can easily be found).
>> Committers are encouraged to review the PR to accept
>> and merge it or reject it or request changes on it;
>> but they can also just indicate that they consider the
>> PR sufficiently complex that a proper second review is
>> needed before merging, or request an extension, etc.
>> To do so they should still leave a "reject" review,
>> even if just saying "objecting to single-review
>> merged; anyone can dismiss after a second review".
>> However, if within another two weeks, no committer
>> voiced any objection (explicitly, i.e. by rejecting),
>> then the PR can indeed be merged on the basis of that
>> single review.
>>
>> To avoid overwhelming the system, any committer can
>> only "sponsor" a single PR at a time.
>>
>> Thoughts?
>>
>> Antony
>> _______________________________________________
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>
> --
> Jody Klymak
> Jody M. Klymak - UVic Ocean Physics
>
>
>
>
>
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I didn't mean to imply that you had a secret agenda in changing the API in
a backward incompatible way. But mistakes happen, and looking for backward
incompatibility has not been a top priority for some core developers
recently, and over time it creates a culture where looking carefully for
backward incompatibility is not part of our reviewing process. Having two
core developers review changes limits the chance of such pull requests
being merged with backward incompatibility. I also think that every API
change, including the addition of keywords, needs to be considered
carefully. Part of the issues we are having in terms of maintenance are
that too many functions are public and many of those don't have a
consistent API with the rest of the library.

To summarize the points that have been agreed upon and the points that
still need to be discussed. I've removed the one about documentation, but
if we accept API changes in this system, it should probably added back as a
point to be discussed.

Agreed upon:
- Has not been commented on by more than one core developer;
- Doesn't fix a release-critical bug;
- Is fully tested.

Still needs to be discussed:
1. Doesn't change the public API;
2. Doesn't add or remove a functionality;
3. Doesn't add or remove a dependency;
4. Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

I'd also like to add:
5. All CI passes (because we have, in the past, ignored some errors on
Travis when we felt tests were flaky)

I maintain that any pull requests that add or remove a functionality should
be reviewed by 2 core developers. I guess our BDFL may have to make the
final call on that one :slight_smile:

My argument for 4. is that long pull requests are harder to review, even if
they are trivial (there are studies on this.). It is thus easier to make a
mistake in reviewing.

In terms of number of pull request per core dev, it is just that more pull
requests dilute our effort in reviewing. The more someone has pull request
open, the less likely they are to be reviewed and the more likely that
developer is to "forget" about them. I don't think we should have a rule on
the number of pull request open per person, but on the different project I
contribute to, I have a rule of thumb to not have more than 5 pull requests
opened. It forces me to finish up the work on the pull requests I have
opened before working on something else.

As for David's point, it just happens that some collaborators and I are
working on understanding factors for newcomer retention and developer
burnout. We've got preliminary results that we are not ready to share but
we are hoping that it'll help on that point.

Cheers,
N

···

On Wed, 16 Jan 2019 at 03:11, Antony Lee <antony.lee at institutoptique.fr> wrote:

Replying to Nelle's points first:

It seems to me that this "uncontroversial but uninteresting" rule is
currently not based on objective criteria. I'm personally not in favor of
removing two core contributors approval for anything that modifies the
API. We have had too many close calls on PR almost merged that had
backward incompatible changes: I realize that some core developers believe
that we are not moving fast enough, on a project with hundreds of thousands
of users, changes to the API should not be considered lightly.

To be clear (and even though it is probably common knowledge that I would
like to evolve the API faster), there is no "secret agenda" of using this
to sneak API breaks through the system.

Here's an attempt at better defining an "uncontroversial but
uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;

Sounds reasonable (with a reasonably flexible interpretation -- similarly
to the "no activity since two weeks, excluding trivial chat"), basically
"no other core dev expressed interest in reviewing it".

- Doesn't change the public API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;

I expect all changes of API to go through the normal route of deprecation
and API change note, which even the first reviewer should make sure are
present before sponsoring the PR for single-review-merge (as an aside, I
guess the first reviewer could even say, "approving, but I don't want to
take the responsibility for being the single reviewer"...). So now you
have a two week period where any other core dev passing by can just see
whether there is an API change note and make their own judgment, including
deciding to block the PR if necessary, based on that change note.
I guess it is reasonable to say "API deprecations or changes and new
functionality should be clearly documented" to help that "skim-through"
review.
As for *adding* functionality, I guess you would have rejected the
ttc-font PR on that premise? (Actually I now see that the additional
functionality was actually not documented :)) Note that this is not some
obscure edge case that no one cares about; it's a feature that has been
requested for years on the tracker.

- Is fully tested;

Also proposed by Jody and now by David, sounds good to me.

- All parameters are fully documented;

(sounds contradictory with "doesn't add a functionality"... if there is no
new functionality it's unlikely there's a new parameter)

- Doesn't fix a release-critical bug;

These tend to all be merged just before the next release is cut anyways
(review dynamics are a bit different in these periods), so I wouldn't worry
about it, but sure.

- Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

I don't actually think this is a good rule; the pdf/ps merge PR is +138
lines, -182 lines but as explained above the change is fairly trivial;
obviously I could have split it into smaller chunks but if anything that
would have made it harder to review.
Conversely (to use an example I have already raised elsewhere)
FIX: Ensuring both x and y attrs of LocationEvent are int by TarasKuzyo · Pull Request #11530 · matplotlib/matplotlib · GitHub (making sure that
LocationEvent.x and LocationEvent.y are integers (as they refer to pixel
locations) rather than floats) is 2 lines of changes in the codebase and 20
lines of test, was reviewed by 2.5 core devs (I left a comment in passing)
and we all missed that there was "problem" with it (it broke mplcursors and
some other pieces of code I have that assume that it is possible to
synthetize LocationEvents pointing to arbitrary places in the canvas).
(Not to derail this discussion into how to evaluate API breaks once
again... but I think these kinds of changes are much more insidious than,
say, removing a function, as the latter would just trigger an
AttributeError that is easily noticed and at worst you just go back to the
previous Matplotlib release, whereas the LocationEvent change was only
caught because it was covered by the mplcursors test suite; otherwise I'd
have been silently generating wrong results due to it...)

To be honest, it also doesn't help that some people have 50+ pull
requests open (Antony? :p).

I guess if the way to fix Matplotlib is to not contribute to Matplotlib
anymore, we have a bigger problem. In fact, I have some pretty big patches
fixing long-standing issues (e.g. for #8550 I have a pure-Python
reimplementation of the fontconfig font weight deduction algorithm,
translated from fontconfig's C implementation) that I don't even bother
turning into PRs, as I know they have no chance of being reviewed and
merged under the current system at least, because no one would care (see
also the bus-factor point below).

It also doesn't help that some PR contain the same code (13117, 13128)
and are being hold off until the other one is merged (also, why is 13117
being hold off for a PR that has been opened afterwards?). IMO, if a PR can
be merged, it should be merged.

That's discussed in
Cleanup matplotlib.use by timhoffm · Pull Request #13117 · matplotlib/matplotlib · GitHub
(FTR I actually agreed on merging 13117 directly, but apparently that's an
API break...)

But we shouldn't make too many exceptions to the two core contributors
rules. It's easier to have two core contributor review a pull request, than
to try to fix API issues on code that has been merged and released. Having
two pairs of eyes on a PR is also a good way to avoid having a bus factor
of 1 on some areas of the library.

There are already huge and central chunks of the library (Agg internals,
PDF/PS) that have a bus factor close to zero. If anything, I hope that
this "drive-by review" system will encourage reviewers to start looking at
places they are less familiar with ("oh yes, I guess this change makes
sense" -- see Eric's reply above) and decrease that.

And then to David's (the code-coverage point is already covered above):

I think it is good remember that (as far as I know) everyone submitting

PRs and everyone reviewing them isn't paid and does so in their spare time;
therefore is no obligation for anyone to review anything on any particular
timescale. One thing that hasn't been discussed is how to increase the
reviewing capacity of the community, which I guess would involve working
out how to attract and retain more regular contributors.

Given the premises "no one is paid to review PRs" and "the reviewing
capacity is too small" (which I agree with), I think there are two
reasonable solutions:
- Make PRs easier to merge (this proposal),
- Increasing to number of core devs (your proposal, but it's not clear to
me whether this number can increase significantly in a short period of
time...).

Antony

On Wed, Jan 16, 2019 at 10:34 AM David Stansby <dstansby at gmail.com> wrote:

I think it is good remember that (as far as I know) everyone submitting
PRs and everyone reviewing them isn't paid and does so in their spare time;
therefore is no obligation for anyone to review anything on any particular
timescale. One thing that hasn't been discussed is how to increase the
reviewing capacity of the community, which I guess would involve working
out how to attract and retain more regular contributors.

re. the proposed changes, I'm +1 modulo objective criteria being agreed
upon. Personally I agree with Nelle's list, with the addition "has 100%
code coverage".

David

On Tue, 15 Jan 2019, 23:46 Nelle Varoquaux <nelle.varoquaux at gmail.com >> wrote:

For the way GitHub sorts pull requests, it is indeed a problem, but
there's a way to sort by "most recently updated." I sometimes use it to
make sure that I review recently updated pull request that don't appear on
the first page.

It seems to me that this "uncontroversial but uninteresting" rule is
currently not based on objective criteria. I'm personally not in favor of
removing two core contributors approval for anything that modifies the
API. We have had too many close calls on PR almost merged that had
backward incompatible changes: I realize that some core developers believe
that we are not moving fast enough, on a project with hundreds of thousands
of users, changes to the API should not be considered lightly.

Here's an attempt at better defining an "uncontroversial but
uninteresting" rule based on objective criteria:
- Has not been commented on by more than one core developer;
- Doesn't change the *public* API;
- Doesn't add or remove a functionality;
- Doesn't add or remove a dependency;
- Is fully tested;
- All parameters are fully documented;
- Doesn't fix a release-critical bug;
- Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

To be honest, it also doesn't help that some people have 50+ pull
requests open (Antony? :p). It also doesn't help that some PR contain the
same code (13117, 13128) and are being hold off until the other one is
merged (also, why is 13117 being hold off for a PR that has been opened
afterwards?). IMO, if a PR can be merged, it should be merged. But we
shouldn't make too many exceptions to the two core contributors rules. It's
easier to have two core contributor review a pull request, than to try to
fix API issues on code that has been merged and released. Having two pairs
of eyes on a PR is also a good way to avoid having a bus factor of 1 on
some areas of the library.

On Tue, 15 Jan 2019 at 15:19, Thomas Caswell <tcaswell at gmail.com> wrote:

I think a distinction between "no one cares" and "no one has bandwidth"
needs to be made.

If you look at the 'pulse' page, we merging 100+ PRs a month (
Pulse · matplotlib/matplotlib · GitHub) so reviews are
happening, the issue is just that some are falling through the cracks.

Tom

On Tue, Jan 15, 2019 at 4:45 PM Antony Lee < >>>> antony.lee at institutoptique.fr> wrote:

Eric,
Neither the ttc font, nor the pdf/ps common code PRs actually touch
any "complex" point regarding fonts or pdf/ps. I have described the ttc
font in my previous message; the pdf/ps PR is really just, look, these two
classes share 80 lines worth of code that's literally copy-pasted, let's
just put that in a common parent class and inherit from it.
Conversely, one font-related PR for which I actually have low hopes of
getting properly reviewed (except on an "sure, I trust you" basis) is
textpath encoding by anntzer · Pull Request #12928 · matplotlib/matplotlib · GitHub, which actually
touches a rather complex point about font encodings (some of which I had to
clarify on the FreeType mailing list). (If anyone wants to have a look at
it, though... :p)
Antony

On Tue, Jan 15, 2019 at 10:36 PM Eric Firing <efiring at hawaii.edu> >>>>> wrote:

Antony,

Your examples illustrate that the problem is often that we don't have
enough people who understand some areas, like fonts and pdf/ps file
formats, to get 2 thorough and knowledgeable reviews in a reasonable
time.

I'm fine with your proposed rule. It should help at least a little
bit.

Eric

On 2019/01/15 9:11 AM, Antony Lee wrote:
> I'm obviously more aware of my own PRs, so here are a few I'd have
put
> up for single-review-merge (note that it's quite possible that
they'd
> have attracted more attention and gotten merged faster under that
> system; that's also the goal...). Obviously other devs may think
about
> other PRs that could have benefitted from the same process.
>
> - Support (first font of) TTC files. by anntzer · Pull Request #9787 · matplotlib/matplotlib · GitHub adds support
for
> the ttc font format (requested since 2014) for png/svg output
(that's
> provided basically for free by FreeType) but not for pdf/ps (that
would
> require more difficult changes). The entire PR comes down to:
> * adding "ttc" as an extension that should be treated like
"ttf"/"otf",
> * adding error handling to pdf/ps to signal these formats are
not
> supported there,
> * tests.
> The PR sat open for 10 months before a first positive review
(because
> no one cares about fonts, I guess) and took another 3 months to
attract
> a second positive review.
>
> - Make FontManager.defaultFont a property, to avoid hardcoding the prefix. by anntzer · Pull Request #12472 · matplotlib/matplotlib · GitHub does a
fairly
> trivial fix to fontList.json to make it reusable for Matplotlibs
> installed in different venvs, got a positive review in one day and
> waited another 2.5 months for a second positive review.
>
> - Factor out common code between pdf and ps backends. by anntzer · Pull Request #9867 · matplotlib/matplotlib · GitHub deduplicates
> completely duplicated code between the pdf and ps backends, mostly
for
> maintainability's sake; it took 7.5 months (and 5 rebases due to
> conflicts) to get a first positive review and another 6 (and around
as
> many rebases) to get a second one.
>
> -----
>
> As for the specifics (as I see it):
> - Someone opens a PR, it gets a positive review, no negative
review, and
> no activity occurs for two weeks (significant activity -- excluding
> trivial chat on the thread).
> - Sponsor (first reviewer, or author if a committer) *pings* all
devs by
> mentioning @matplotlib/developers on the PR thread with the intent
to
> single-review-merge, and labels the PR accordingly.
> - The PR can still be reviewed/merged/rejected by the normal review
> process. However, if no one explicitly opposes the merge within
two
> weeks, anyone can merge it at that point (including by self-merge).
>
> I would not exclude all API changes from the process. For example,
>
https://github.com/matplotlib/matplotlib/pull/13173/commits/e90d264f3e5a263ef57243a2af86b46ab74ccc16
> deprecates (and prepares for deletion) two parameters to imshow()
that
> have had no effect since 2006. Let's pretend for a second this
commit
> was a single independent PR (and not an example to showcase the
> parameter-deprecating decorator...); if it started being forgotten
I
> would have proposed it for single-review-merge (again, note that if
> you're worried about the change, you don't need to reject the PR;
you
> can just say, I think this API change needs to be approved by a
second
> reviewer and that'll block the single-review-merge just as well).
>
> Antony
>
> On Tue, Jan 15, 2019 at 7:46 PM Nelle Varoquaux >>>>>> > <nelle.varoquaux at gmail.com <mailto:nelle.varoquaux at gmail.com>> >>>>>> wrote:
>
> The proposed scheme by Paul doesn't seem reasonable to me. Core
> contributor A or committers needs to actively reach out to other
> core contributors: labeling is not enough IMO.
>
>
> On Tue, 15 Jan 2019 at 10:37, Jody Klymak <jklymak at uvic.ca >>>>>> > <mailto:jklymak at uvic.ca>> wrote:
>
>
>
>> On 15 Jan 2019, at 10:20, Paul Hobson <pmhobson at gmail.com >>>>>> >> <mailto:pmhobson at gmail.com>> wrote:
>>
>> I think this would be a good policy as well. Can I get some
>> clarification on the flow? The way I understand it:
>>
>> 1) Someone (committer, contributor, or first-timer) opens a
>> simple PR
>> 2) Committer A reviews it, adds a "single-review-merge"
label,
>> then digitally walks away
>> 3) No less than two weeks later, Committer B sees the PR,
>> notices the label, opens it up, and merges without
reviewing.
>
> If there is a Committer B, I think they should at least
look at
> the PR to make sure it doesn?t have any hidden API changes,
or
> introduce anything hostile.
>
> The point here is that getting the third person to look at
a PR
> is proving quite difficult, and if the rest of the folks
with
> the commit bit haven?t looked at a PR for a month, even
after
> being warned, then silence indicates consent.
>
> Note that only folks with the commit bit can label PRs, so
> anyone flagging a PR like this is implicitly trusted to not
be
> wreaking havoc, and not doing this for major changes.
Since we
> all curate our own PRs, I rather expect that the PR
contributor
> will often be the person who adds the flag. Whether we
want to
> allow a self-merge at that point is up for debate, but if
not,
> then folks need to get in the habit of looking at old
flagged
> PRs and merging them.
>
> I think a huge problem we have is the LIFO default sort of
the
> github PR queue, and that any PR not on the first page
might as
> well be closed for all the attention it will get without
> constant nagging.
>
> Cheers, Jody
>
>> Does that capture a successful "single-review-merge"
lifecycle?
>> -paul
>>
>> On Tue, Jan 15, 2019 at 9:57 AM Nelle Varoquaux >>>>>> >> <nelle.varoquaux at gmail.com <mailto: >>>>>> nelle.varoquaux at gmail.com>> >>>>>> >> wrote:
>>
>> Hello,
>>
>> Overall, I think this is a good idea, but I would like
>> specifics on what "uncontroversial but uninteresting"
PR
>> mean. IMO, that should exclude any PR with API changes.
>>
>> Cheers,
>> N
>>
>> On Tue, 15 Jan 2019 at 06:00, Antony Lee >>>>>> >> <anntzer.lee at gmail.com <mailto:anntzer.lee at gmail.com>> >>>>>> wrote:
>>
>> Hi all,
>>
>> During the weekly dev call, I proposed to amend
the PR
>> merge rules, following an initial comment on Github
>> [
Decorator for deleting a parameter with a deprecation period. by anntzer · Pull Request #13173 · matplotlib/matplotlib · GitHub].

>> There was general agreement among the devs present
>> (Tom, Hannah, Jody, and myself), so I'm putting it
>> here for discussion. The objective of this change
is
>> to prevent "uncontroversial but uninteresting" PRs
>> from falling into oblivion, and try to decrease the
>> size of the open PR stack.
>>
>> The current rule is that a PR needs positive
reviews
>> (from two committers, and excluding the author if a
>> committer) to be merged, except that doc-only PRs
>> (docstrings, rst) only needs a single positive
review.
>>
>> I am proposing that, if a (non-doc) PR already has
one
>> positive review, but no activity on that PR has
>> occurred for two weeks (exact time interval up to
>> bikeshedding) [Jody suggests: and the PR has 100%
code
>> coverage], then a committer (either the first
>> reviewer, or the author if a committer) can suggest
>> that it be merged on the basis of that single
review.
>> To do so, the "sponsor" should ping all developers
>> (@matplotlib/developers) on that issue indicating
that
>> intent, and add a "single-review-merge" label on
the
>> PR (so that these PRs can easily be found).
>> Committers are encouraged to review the PR to
accept
>> and merge it or reject it or request changes on it;
>> but they can also just indicate that they consider
the
>> PR sufficiently complex that a proper second
review is
>> needed before merging, or request an extension,
etc.
>> To do so they should still leave a "reject" review,
>> even if just saying "objecting to single-review
>> merged; anyone can dismiss after a second review".
>> However, if within another two weeks, no committer
>> voiced any objection (explicitly, i.e. by
rejecting),
>> then the PR can indeed be merged on the basis of
that
>> single review.
>>
>> To avoid overwhelming the system, any committer can
>> only "sponsor" a single PR at a time.
>>
>> Thoughts?
>>
>> Antony
>> _______________________________________________
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>> Matplotlib-devel at python.org
>> <mailto:Matplotlib-devel at python.org>
>>
Matplotlib-devel Info Page
>>
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>> <mailto:Matplotlib-devel at python.org>
>>
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>>
>> _______________________________________________
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Matplotlib-devel at python.org>
>> Matplotlib-devel Info Page
>
> --
> Jody Klymak
> Jody M. Klymak - UVic Ocean Physics
>
>
>
>
>
> _______________________________________________
> Matplotlib-devel mailing list
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>
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>
>
> _______________________________________________
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> Matplotlib-devel Info Page
>

_______________________________________________
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Matplotlib-devel at python.org
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--
Thomas Caswell
tcaswell at gmail.com
_______________________________________________
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I didn't mean to imply that you had a secret agenda in changing the API in
a backward incompatible way. But mistakes happen, and looking for backward
incompatibility has not been a top priority for some core developers
recently, and over time it creates a culture where looking carefully for
backward incompatibility is not part of our reviewing process. Having two
core developers review changes limits the chance of such pull requests
being merged with backward incompatibility. I also think that every API
change, including the addition of keywords, needs to be considered
carefully. Part of the issues we are having in terms of maintenance are
that too many functions are public and many of those don't have a
consistent API with the rest of the library.

Again, you may note that I have fairly few PRs that introduce new
functionality; most of the API changes I PR'd actually deprecate and later
remove functions that "should not have been public" (I have sort of given
up on making things consistent in an backcompatible manner). So in that
respect I am mostly trying to improve maintanability...

To summarize the points that have been agreed upon and the points that
still need to be discussed. I've removed the one about documentation, but
if we accept API changes in this system, it should probably added back as a
point to be discussed.

Agreed upon:
- Has not been commented on by more than one core developer;
- Doesn't fix a release-critical bug;
- Is fully tested.

Still needs to be discussed:
1. Doesn't change the public API;
2. Doesn't add or remove a functionality;
3. Doesn't add or remove a dependency;
4. Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

I'd also like to add:
5. All CI passes (because we have, in the past, ignored some errors on
Travis when we felt tests were flaky)

Agreed on 5.

I maintain that any pull requests that add or remove a functionality
should be reviewed by 2 core developers. I guess our BDFL may have to make
the final call on that one :slight_smile:

Happy to let Tom decide, but again I would say that "add or remove a
functionality" is not always an objective feature either (e.g., does the
LocationEvent-integer PR qualify?).

My argument for 4. is that long pull requests are harder to review, even
if they are trivial (there are studies on this.). It is thus easier to make
a mistake in reviewing.

As I already mentioned, there have been cases of 2-line PRs (+ 20 lines of
*new* tests) making backwards incompatible changes, whereas some 100+ lines
PR are essentially copy-paste trivialities, so I really don't buy the
argument.

In terms of number of pull request per core dev, it is just that more pull
requests dilute our effort in reviewing. The more someone has pull request
open, the less likely they are to be reviewed and the more likely that
developer is to "forget" about them. I don't think we should have a rule on
the number of pull request open per person, but on the different project I
contribute to, I have a rule of thumb to not have more than 5 pull requests
opened. It forces me to finish up the work on the pull requests I have
opened before working on something else.

Frankly it's not clear what "finish up the work" is supposed to mean. If
you look at the PRs I've mentioned above they have been merged with (close
to) no changes (except for repeated rebases on master...) after the
6-to-12-month review period, so essentially all the work was done from the
beginning.

As for David's point, it just happens that some collaborators and I are
working on understanding factors for newcomer retention and developer
burnout. We've got preliminary results that we are not ready to share but
we are hoping that it'll help on that point.

Happy to hear anything that could be done to help on that point. But I
guess I'll take advantage of this to reply to Tom's remark as well

[Tom] I want to push back strongly on the notion that "did not review -->

does not care". As as already been discussed above there are many other
reasons someone does not comment (for example "I _do_ care about this, but
I {do not have time, am too tired and cranky, ...} to properly review this
now").

I'm not pointing fingers at anyone not doing their review share, and once
again totally agree with David's point regarding no one being paid.
However, you have to realize that the consequences of insufficient review
volume is that real improvements are not getting in (either because the PRs
stall out, or (in my case) because I don't even bother PR'ing them anymore
and just live-patch matplotlib locally), and saying "it's no-one's fault"
(which is true) is not going to help.

Cheers,

N

Antony
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···

On Wed, Jan 16, 2019 at 6:26 PM Nelle Varoquaux <nelle.varoquaux at gmail.com> wrote:

I think real improvements not getting in at the rate they are submitted is
just how it works; if I started submitting a PR a day for the next 50 days
I would expect a good chunk of them sit there un-reviewed based on our
current rate of merging things, and that's fine. The developers as a whole
have a total reviewing rate, which is unpredictable and finite by the very
nature of this being an open-source project where no-one is obliged to do
anything. If we want to adjust reviewing rules to increase 'productivity'
that seems fine to me, but I don't think we should be doing it with the end
goal of being able to review at the rate that code is submitted (or any
particular other rate).

re. large diff PRs, I find 100+ line PRs that are just copy and paste
really hard to review - it's pretty dull for me trying to work out if code
has been copy/pasted exactly without any errors (if there's an easier way
to review stuff like this instead of checking every line please let me
know!).

David

···

On Wed, 16 Jan 2019 at 17:54, Antony Lee <antony.lee at institutoptique.fr> wrote:

On Wed, Jan 16, 2019 at 6:26 PM Nelle Varoquaux <nelle.varoquaux at gmail.com> > wrote:

I didn't mean to imply that you had a secret agenda in changing the API
in a backward incompatible way. But mistakes happen, and looking for
backward incompatibility has not been a top priority for some core
developers recently, and over time it creates a culture where looking
carefully for backward incompatibility is not part of our reviewing
process. Having two core developers review changes limits the chance of
such pull requests being merged with backward incompatibility. I also think
that every API change, including the addition of keywords, needs to be
considered carefully. Part of the issues we are having in terms of
maintenance are that too many functions are public and many of those don't
have a consistent API with the rest of the library.

Again, you may note that I have fairly few PRs that introduce new
functionality; most of the API changes I PR'd actually deprecate and later
remove functions that "should not have been public" (I have sort of given
up on making things consistent in an backcompatible manner). So in that
respect I am mostly trying to improve maintanability...

To summarize the points that have been agreed upon and the points that
still need to be discussed. I've removed the one about documentation, but
if we accept API changes in this system, it should probably added back as a
point to be discussed.

Agreed upon:
- Has not been commented on by more than one core developer;
- Doesn't fix a release-critical bug;
- Is fully tested.

Still needs to be discussed:
1. Doesn't change the public API;
2. Doesn't add or remove a functionality;
3. Doesn't add or remove a dependency;
4. Is less than XX lines of code. (Long PR are harder to review, and thus
the likelihood of one core dev not noticing a problem is higher). Threshold
needs to be defined.

I'd also like to add:
5. All CI passes (because we have, in the past, ignored some errors on
Travis when we felt tests were flaky)

Agreed on 5.

I maintain that any pull requests that add or remove a functionality
should be reviewed by 2 core developers. I guess our BDFL may have to make
the final call on that one :slight_smile:

Happy to let Tom decide, but again I would say that "add or remove a
functionality" is not always an objective feature either (e.g., does the
LocationEvent-integer PR qualify?).

My argument for 4. is that long pull requests are harder to review, even
if they are trivial (there are studies on this.). It is thus easier to make
a mistake in reviewing.

As I already mentioned, there have been cases of 2-line PRs (+ 20 lines of
*new* tests) making backwards incompatible changes, whereas some 100+ lines
PR are essentially copy-paste trivialities, so I really don't buy the
argument.

In terms of number of pull request per core dev, it is just that more
pull requests dilute our effort in reviewing. The more someone has pull
request open, the less likely they are to be reviewed and the more likely
that developer is to "forget" about them. I don't think we should have a
rule on the number of pull request open per person, but on the different
project I contribute to, I have a rule of thumb to not have more than 5
pull requests opened. It forces me to finish up the work on the pull
requests I have opened before working on something else.

Frankly it's not clear what "finish up the work" is supposed to mean. If
you look at the PRs I've mentioned above they have been merged with (close
to) no changes (except for repeated rebases on master...) after the
6-to-12-month review period, so essentially all the work was done from the
beginning.

As for David's point, it just happens that some collaborators and I are
working on understanding factors for newcomer retention and developer
burnout. We've got preliminary results that we are not ready to share but
we are hoping that it'll help on that point.

Happy to hear anything that could be done to help on that point. But I
guess I'll take advantage of this to reply to Tom's remark as well

[Tom] I want to push back strongly on the notion that "did not review -->

does not care". As as already been discussed above there are many other
reasons someone does not comment (for example "I _do_ care about this, but
I {do not have time, am too tired and cranky, ...} to properly review this
now").

I'm not pointing fingers at anyone not doing their review share, and once
again totally agree with David's point regarding no one being paid.
However, you have to realize that the consequences of insufficient review
volume is that real improvements are not getting in (either because the PRs
stall out, or (in my case) because I don't even bother PR'ing them anymore
and just live-patch matplotlib locally), and saying "it's no-one's fault"
(which is true) is not going to help.

Cheers,

N

Antony

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I think real improvements not getting in at the rate they are submitted is
just how it works; if I started submitting a PR a day for the next 50 days
I would expect a good chunk of them sit there un-reviewed based on our
current rate of merging things, and that's fine. The developers as a whole
have a total reviewing rate, which is unpredictable and finite by the very
nature of this being an open-source project where no-one is obliged to do
anything. If we want to adjust reviewing rules to increase 'productivity'
that seems fine to me, but I don't think we should be doing it with the end
goal of being able to review at the rate that code is submitted (or any
particular other rate).

The end goal is not to set a specific rate, but it is indeed to try to
raise that rate up. Obviously we could also throw our hands up and say
nothing can be done about it, but that seems a bit defeatist.

Right now, I would bet that a lot of PRs go in with exactly two reviewers
having gone through them and no other reviewer having even skimmed them.
If anything, I believe that the system I propose will increase the number
of core-devs that'll have at least skimmed through the PR (all you need to
do, if you want to participate, is to check your github notifications once
every other week, whereas right now you'd actually need to pay attention to
each PR as it is being submitted), and it is quite likely that 1 in-depth
reviewer + 3-4 skim-throughs works as well, if not better, than 2
"in-depth" reviews (especially when the second one is sometimes "oh, that
looks fine and it's already been approved once, let's just commit it").

re. large diff PRs, I find 100+ line PRs that are just copy and paste
really hard to review - it's pretty dull for me trying to work out if code
has been copy/pasted exactly without any errors (if there's an easier way
to review stuff like this instead of checking every line please let me
know!).

Frankly, for a PR like that, I would just check that no function is missing
and that everything is test-covered (without changes to the tests), and (in
case you want to be sure) skim through the code to see that the PR author
has not added a sneaky vulnerability that allows them to take over the
user's computer... (In other words, I don't think a line-by-line check
matters for such cases.)

Antony
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···

On Wed, Jan 16, 2019 at 7:36 PM David Stansby <dstansby at gmail.com> wrote:

Apologies, my previous email was unnecessarily negative...

I think the new system is a good idea, so here's where we seem to be. In
terms of process:

1) PR opened
2) PR gets 1 positive review
3) 2 weeks after review the PR gets *no other significant activity,
*and *qualifies
for simpler review*
4) PR opener or reviewer 1 pings all Matplotlib devs
5) If 2 weeks after pinging no other significant activity has occurred, PR
can be merged by PR opener or reviewer 1

Does everyone agree on this? The bits I've put in bold still need to be
defined; I don't have time now, but can provide a summary of these later.

David

···

On Thu, 17 Jan 2019 at 00:48, Antony Lee <antony.lee at institutoptique.fr> wrote:

On Wed, Jan 16, 2019 at 7:36 PM David Stansby <dstansby at gmail.com> wrote:

I think real improvements not getting in at the rate they are submitted
is just how it works; if I started submitting a PR a day for the next 50
days I would expect a good chunk of them sit there un-reviewed based on our
current rate of merging things, and that's fine. The developers as a whole
have a total reviewing rate, which is unpredictable and finite by the very
nature of this being an open-source project where no-one is obliged to do
anything. If we want to adjust reviewing rules to increase 'productivity'
that seems fine to me, but I don't think we should be doing it with the end
goal of being able to review at the rate that code is submitted (or any
particular other rate).

The end goal is not to set a specific rate, but it is indeed to try to
raise that rate up. Obviously we could also throw our hands up and say
nothing can be done about it, but that seems a bit defeatist.

Right now, I would bet that a lot of PRs go in with exactly two reviewers
having gone through them and no other reviewer having even skimmed them.
If anything, I believe that the system I propose will increase the number
of core-devs that'll have at least skimmed through the PR (all you need to
do, if you want to participate, is to check your github notifications once
every other week, whereas right now you'd actually need to pay attention to
each PR as it is being submitted), and it is quite likely that 1 in-depth
reviewer + 3-4 skim-throughs works as well, if not better, than 2
"in-depth" reviews (especially when the second one is sometimes "oh, that
looks fine and it's already been approved once, let's just commit it").

re. large diff PRs, I find 100+ line PRs that are just copy and paste
really hard to review - it's pretty dull for me trying to work out if code
has been copy/pasted exactly without any errors (if there's an easier way
to review stuff like this instead of checking every line please let me
know!).

Frankly, for a PR like that, I would just check that no function is
missing and that everything is test-covered (without changes to the tests),
and (in case you want to be sure) skim through the code to see that the PR
author has not added a sneaky vulnerability that allows them to take over
the user's computer... (In other words, I don't think a line-by-line check
matters for such cases.)

Antony

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