0.28b1: (spurious?) Warning when extension name deliberately doesn't match python name

[jamadden]

(First, let me say that Cython is fantastic. I've been using git checkouts of 0.28a much more in gevent 1.3a2 and it has led to many improvements. Thanks!)

One of the new features (called a bugfix) in Cython 0.28 is the ability to have an Extension that compiles a .py file to a different extension name (#2038). This is extremely useful for creating optional accelerator modules (especially on PyPy). gevent has been using it as such (and it's made my life much easier, thanks!).

However, when you do so, you get a warning:

# setup.py
from Cython.Build import cythonize
from setuptools import Extension

foo = Extension(name='_foo',
                sources=['foo.py'])

cythonize([foo])

$ python setup.py
Warning: Extension name '_foo' does not match fully qualified name 'foo' of 'foo.py'

Is this warning still necessary now that the generated code is correct? Or am I doing something wrong?

I could see the argument that in the usual case the warning could be useful to avoid mistakes, but then it would be nice to have a way to silence the warning when it's done deliberately.

If there's something easy to do here I could try to work up a PR.

[jamadden]

Thanks!