I'm thinking setuptools should allow you to specify that one or more C
extensions in a project are optional.
At minimum, there would then be a command-line option you could give to
easy_install to say, "don't build any optional extensions", so if you don't
have a compiler or need a cross-platform egg, you can skip those extensions.
There would also need to be a way to specify this when using the regular
This feature would address projects that include optional C versions of
certain code, that can fall back to pure Python implementations.
It would not address projects that have C extensions requiring external
libraries that might or might not exist. (Such as Twisted, for instance,
but Twisted falls into the category of projects requiring "extreme
measures" to be supported anyway.)