So, if I got it right, I compile and install libpng in a local directory, point an environment variable MPLIB_BASE
to the /usr/local equivalent (not to the actual directory containing libpng.so, usually /usr/local/lib) and then run
python setup.py build
python setup.py install --prefix $HOME/local
This is getting really frustrating, did it, same error:
ImportError: /homes/morlet/aborghgr/local/lib/python2.3/site-packages/matplotlib/_nc_image.so: undefined symbol: png_set_sBIT
And png_set_sBIT is present in the local install of libpng, that one isn't stripped of symbols.