It would appear something else is going on here other than
> straightforward issues of whether or not I'm running
> interactively. Unfortunately, the wild differences between
> the two gdb backtraces suggest that I'm going to have to
> drag out Electric Fence or some other malloc debugger to
> figure out what's wrong (oh joy, oh happy thought...), which
> I don't have time for at the moment.
> Any simpler suggestions?
Arggg. Sorry you are having so much trouble.
Two suggestions: try running different backends with a minimal script
from pylab import plot, savefig
run from the command line with
> python myscript.py -dPS --verbose-helpful
> python myscript.py -dAgg --verbose-helpful
and see if you get segfaults on both or either of the postscript and
agg pure image backends (taking gtk and attendant complexities out of
the loop). The --verbose-helpful information will be useful to post.
Also run with --verbose-debug which produces lots of extra
information like which fonts are being loaded etc. I have seen some
fonts which have crashed the mpl extension code, and I've tried to fix
these bugs when I find them.
If none of this is enlightening, do
> sudo rm -rf build /your/path/to/site-packages/matplotlib
and toggle the VERBOSE flag to True in setup.py and rebuild/reinstall.
This will cause the extension code to spew lots of extra debug
information, and usually helps narrow the locus of the bad code.
Let me know...