tests/sitecustomize.py

copies: add a HASCOPIESINFO flag to highlight rev with useful data

If some files changes that may impact copy tracing are detected, we set this
flag. This helps the copy tracing algorithm to skip fetching possibly expensive
data when unnecessary.

Differential Revision: https://phab.mercurial-scm.org/D9139

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