i18n: fix coding tag unsupported by xgettext Running `make update-pot` currently fails with the following error: xgettext: mercurial/metadata.py:1: Unknown encoding "utf8". Proceeding with ASCII instead. xgettext: Non-ASCII string at mercurial/metadata.py:311. Please specify the source encoding through --from-code or through a comment as specified in http://www.python.org/peps/pep-0263.html. Differential Revision: https://phab.mercurial-scm.org/D9260

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