I confirm that under Python 2.7.2 while trying to build a 3rd-party package (from rdkit.org) I get the error Linking CXX shared library ../../lib/libRDBoost.dylib ld: warning: path '/usr/local/lib/libpython2.7.a' following -L not a directory Undefined symbols: "_environ", referenced from: _initposix in libpython2.7.a(posixmodule.o) (maybe you meant: cstring=ignore_environment) ld: symbol(s) not found collect2: ld returned 1 exit status My Python-2.7 was configured with "./configure" and is not a framework install. I applied the patch to my local 2.7 copy and the third party package builds without a problem.