tests/sitecustomize.py

setup: use setuptools on Windows (issue5400)

We've had a long, complicated history with setuptools. We want to
make it the universal default. But when we do, it breaks things.

`python setup.py build` is broken on Windows today. Forcing
the use of setuptools via FORCE_SETUPTOOLS=1 unbreaks things.

Since the previous bustage with making setuptools the default
was on !Windows, it seems safe to move ahead with the setuptools
transition on Windows. So this patch does that.

from __future__ import absolute_import
import os

if os.environ.get('COVERAGE_PROCESS_START'):
    try:
        import coverage
        import uuid

        covpath = os.path.join(os.environ['COVERAGE_DIR'],
                               'cov.%s' % uuid.uuid1())
        cov = coverage.coverage(data_file=covpath, auto_data=True)
        cov._warn_no_data = False
        cov._warn_unimported_source = False
        cov.start()
    except ImportError:
        pass