some update removed /usr/local/lib/libpng15.15.dylib which is required by mplotqueries(matplotlib)

[jimoleary]

This is more of a note in case anyone else encounters the same problem but ..
Some update on my Mac (not sure exactly what) seems to have removed libpng15.15.dylib or maybe the dependency changed in matplotlib.

Anyway a quick fix to get mplotqueries loading matplotlib was to create a link from libpng16.16.dylib to libpng15.15.dylib:

$ ln -s  /usr/local/lib/libpng16.16.dylib  /usr/local/lib/libpng15.15.dylib

Note this means mplotqueries can't save any files, I got the following error:

libpng warning: Application built with libpng-1.5.17 but running with 1.6.17
Traceback (most recent call last):
File "/usr/local/Cellar/python/2.7.4/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.py", line 472, in save_figure
self.canvas.print_figure(filename)
File "/usr/local/Cellar/python/2.7.4/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 2220, in print_figure
*_kwargs)
File "/usr/local/Cellar/python/2.7.4/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 1962, in print_png
return agg.print_png(_args, **kwargs)
File "/usr/local/Cellar/python/2.7.4/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 517, in print_png
filename_or_obj, self.figure.dpi)
RuntimeError: Could not create write struct

The following appears to have fixed the issue more permanently but may be overkill:

$ curl --remote-name --location http://download.sourceforge.net/libpng/libpng-1.5.21.tar.gz
$ tar -zxvf libpng-1.5.21.tar.gz
$ cd libpng-1.5.21
$ ./configure --enable-maintainer-mode
$ make maintainer-clean
$ LIBTOOLIZE=glibtoolize  ./autogen.sh --maintainer --clean
$ LIBTOOLIZE=glibtoolize  ./autogen.sh --maintainer 
$ ./configure
$ make
$ make install

[jimoleary]

looks like it was also already in /opt/X11/lib/libpng15.15.dylib