Matplotlib and Mac OS 10.5.6 compiler error resolved
Just for future reference, and others in the same situation:
I tried to install MatPlotLib (0.98.5.2), the Python graphing library, on my Mac. I was initially trying ‘easy_install’; when it failed I tried it from source. My problem seems to be that the MacPorts project installs libraries that aren’t necessarily compatible with other applications not using Ports.
In order to get the compile to work, I had to uninstall my libpng macPorts files (and with them the Ghostscript and TeTex libraries), and finally, since I had the same error as reported here, my fontconfig and freetype libraries. Once they were uninstalled, I downloaded freetype from the sourceforge page, ditto libpng. After that, I no longer received the error. The advice given on the Matplotlib mailing list scared me (edit all my Python config files!?), so I just scanned the linker error and thought the freetype library might have been the problem. Sure enough …
Matplotlib does have an abnormal number of dependencies, as I recall one of the reasons it wasn’t used with DrProject.
I also have been finding that MacPorts is less than useful: most software is available as a package for Macs, and it introduces too many conflicting libraries. It’s a good effort, but really, these types of package managers only work really well when used exclusively, like I do on Ubuntu.