as per recent sphinx (I got 1.0.6 where, and with 1.0.1 it worked
fine), the image 'formats' is loaded as a unicode object, and so it's
no more a str as previously identified in
lib/matplotlib/sphinxext/plot_directive.py: the attached patch make
the doc be buildable again with 1.0.6 and should be backportable.
60_doc_output_format.patch (658 Bytes)