I need to copy this file in another test too, so I moved the support
code to distutils.tests.support and improved it to use proper skip
machinery instead of custom print/return/test suite fiddling.
Contrary to my similar change in distutils tests, I did not add support
for finding xxmodule.c when running a test from the tests directory,
because in that case my compiler didn’t find Python.h, so I figured it’s
better to skip than to fail.
packaging.tests.support.TempdirManager: removing the current directory is not
allowed on Windows or Solaris. Store the current directory and restore it
before removing the temporary directory (which is used as the working directory
during the tests).
I’m afraid my docstring is not as clear as it should be, but I can’t
find a concise way of describing what the code does. Suggestions for
improvements welcome.