Looks like gevent needs it, otherwise I get:

make[1]: Entering directory `/home/rgs/devel/kazoo-github/build/gevent'

/home/rgs/devel/kazoo-github/bin/python util/cythonpp.py -o gevent.core.c gevent/core.ppyx

Running cython -o gevent.core.c gevent/core.pyx  # !EV_USE_SIGNALFD && !defined(LIBEV_EMBED) && !defined(_WIN32)

sh: cython: command not found

Traceback (most recent call last):

  File "util/cythonpp.py", line 801, in <module>

    process_filename(filename, options.output_file)