tests/sitecustomize.py

typing: add trivial type hints to `mercurial.scmutil`

There's still a lot to go, but there's a lot here already, so I tried to keep it
to obvious/trivial things.  I didn't bother with contexts, matchers, and
revisions that can be `bytes | int | None`.

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