view tests/sitecustomize.py @ 43912:a89381e04c58

procutil: try and avoid angering CoreFoundation on macOS

We've seen failures like this:

    objc[57662]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called.
    objc[57662]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.

I think this is due to forking off some background processes during
`hg update` or similar. I don't have any conclusive proof this is the
fork() call that's to blame, but it's the most likely one since the
regular `hg update` codepath uses the other fork() invocation (via
workers) and we don't get this report from non-Google macOS users.

Ugh.

Differential Revision: https://phab.mercurial-scm.org/D7615

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