A zc.buildout extension to befriend mr.developer and Cython.
Buildout and mr.developer play nice together, until Cython join the party. There are no unified way to detect/use Cython, some of them (gevent) just use cython command from PATH or from CYTHON environment variable, others just try to import Cython modules directly from setup.py.
Add mr.cython to the extensions entry in your [buildout] section:
[buildout] extensions = mr.cython
If you use mr.developer, add mr.cython right after them:
[buildout] extensions = mr.developer mr.cython
This implicitly install cython into your bin/ directory, and allow setup.py from subsequent developed packages find cython in path, and allow import Cython.* namespace from them. Only eggs from develop line of [buildout] are affected, including eggs pulled by mr.developer.