Hello,
It looks like the zlib website removes previous version of its library that were previously available for download, so the part in make.osx where http://www.zlib.net/zlib-1.2.3.tar.gz is fetched now fails (since the current version is 1.2.4). The error in the matplotlib building is not explicit enough (incorrect archive type) - maybe one could catch such 404s and print out an error suggesting to increase the ZLIBVERSION variable?
I tried changing ZLIBVERSION to 1.2.4 and the following occurs when building zlib:
...
gcc -arch i386 -arch x86_64 -I/Users/tom/install/include -I/Users/tom/install/include/freetype2 -isysroot /Developer/SDKs/MacOSX10.6.sdk -c -o inftrees.o inftrees.c
gcc -arch i386 -arch x86_64 -I/Users/tom/install/include -I/Users/tom/install/include/freetype2 -isysroot /Developer/SDKs/MacOSX10.6.sdk -c -o trees.o trees.c
gcc -arch i386 -arch x86_64 -I/Users/tom/install/include -I/Users/tom/install/include/freetype2 -isysroot /Developer/SDKs/MacOSX10.6.sdk -c -o uncompr.o uncompr.c
gcc -arch i386 -arch x86_64 -I/Users/tom/install/include -I/Users/tom/install/include/freetype2 -isysroot /Developer/SDKs/MacOSX10.6.sdk -c -o zutil.o zutil.c
make[1]: *** No rule to make target `libz.dylib', needed by `install-libs'. Stop.
make[1]: *** Waiting for unfinished jobs....
make: *** [zlib] Error 2
If I manually go to the zlib directory and type make, it builds without a problem, so it looks like there is some kind of problem in the make.osx script.
Thanks in advance for any help,
Thomas