2009/3/27 P.J. Eby <pje@telecommunity.com>:

Also, it's quite likely that platform-specific dependencies may exist as well.  It might be possible to accommodate these things with a sufficiently flexible format, but currently, the only way to handle them with distutils/setuptools is in the setup script.

Yes, we are working on these particular issues when some metadata require some code to run. But most of the time, a package is able to express its dependencies in a static file. Regards Tarek