How can I install the Python library 'gevent' on Mac OS X Lion

Question

Python library gevent, version 0.13.6 (the current version on PyPI) will not pip install on OS X Lion, Python 2.7 (and probably others.) It works f

Answer 1

CFLAGS='-std=c99' pip install gevent

See in: Can't install gevent OSX 10.11

on OS X 10.11, clang uses c11 as the default, so just turn it back to c99.