[Matplotlib-users] How to make matplotlib use my own libpng over the systemwide

[Ondřej Č. <ond...@gm...>]

Hi,

As part of building matplotlib for the one python based distribution [1],
I want to always link against our own version of libpng, even if there
is some other systemwide version available. I am on linux (Ubuntu).

Currently, here is what I am doing:

CFLAGS="-I$PNG/include -I$FREETYPE/include
-I$FREETYPE/include/freetype2" LDFLAGS="-L$FREETYPE/lib -L$PNG/lib
-Wl,-rpath=$PNG/lib" $PYTHON/bin/python setup.py build
$PYTHON/bin/python setup.py install

Where $PNG and $FREETYPE points to our own versions. On a computer
with no systemwide version of png, this works great. Question:

1) If I don't specify the -rpath option, then libpng.so will fail to
be found at runtime. Is there any other recommended way to go around
this? I don't want to use LD_LIBRARY_PATH.

On a computer with systemwide version available, unfortunately the
systemwide version gets picked up instead. I think it's because of
this:

pkg-config --libs --cflags libpng
-I/usr/include/libpng12  -lpng12

so matplotlib simply calls this (right?) and uses the systemwide
version. Question:

2) How do I force matplotlib to use my own version instead?


I would highly appreciate any input, especially on 2). We have our own
issue open for this at [2] if you are interested for the background.
The merged mpl PR [3] is a little related, but doesn't answer my
questions.

Thanks,
Ondrej


[1] https://github.com/hashdist/python-hpcmp2/

[2] https://github.com/hashdist/python-hpcmp2/issues/53

[3] https://github.com/matplotlib/matplotlib/pull/1884