package_python_2_7_matplotlib_1_4 can fail due to package_freetype_2_5_2 setting environment variables

[dpryan79]

I've recently run into problems getting package_python_2_7_matplotlib_1_4 to install on Galaxy within Docker (yes, this is the instance from @bgruening). The reason seems to be that matplotlib's setupext.py script needs pkg-config --cflags freetype2 to return something, but package_freetype_2_5_2 sets C_INCLUDE_PATH and CPLUS_INCLUDE_PATH. If one runs pkg-config --cflags --debug freetype2 then one can see that the appropriate Cflags: line is then excluded, since pkg-config will only output what's required. Reverting the environment changes from done by package_freetype_2_5_2 seems to fix that, though a likely better solution would be to modify the tool_dependencies.xml file from matplotlib to just have it exclude paths from the aforementioned environment variables.

[bgruening]

This seem to be a real problem on the matplotlib site. Since we can not remove an environment variable I see no other solution to remove it from the freetype package. Or create a new on without these exports and use this one solely for matplotlib.

@erasche any ideas here?

[hexylena]

@bgruening okay, read over it now. yikes.

No, I really don't have any ideas. I don't like the idea of a special package just for matplotlib, since there's definitely an underlying issue if pkg-config won't work nicely. Maybe someone has time to dig into why pkg-config doesn't play nicely with C*_INCLUDE PATHs. I'll poke it after lunch

[bgruening]

@erasche this seems to be a matplotlib error as say do not use the correct variables. Not sure why :(

[dpryan79]

@erasche: pkg-config is doing the correct thing. Compilers like gcc/clang/etc. look through directories specified by -I options first, followed by those set in C*_INCLUDE_PATH and finally the default system directories (e.g., /usr/include) when looking for headers. Since disks aren't always fast and many programs will require compiling a large number of files, it's best if the compiler doesn't need to look through the same directory twice. My understanding is that that's why pkg-config is behaving in this manner.

Since this is completely the fault of matplotlib, I'll post a bug report there. That won't resolve the immediate problem but will at least prevent this in the future :)

[dpryan79]

Looks like this will get fixed in matplotlib 1.5.1 due to matplotlib/matplotlib#5578.

[dpryan79]

This is fixed now, I'll close it.