revset: do not rewrite ':y' to '0:y' (issue5385)
That's no longer valid since the revision 0 may be hidden. Bypass validating
the existence of '0' and filter it by spanset.
from __future__ import absolute_import
import os
if os.environ.get('COVERAGE_PROCESS_START'):
try:
import coverage
import random
# uuid is better, but not available in Python 2.4.
covpath = os.path.join(os.environ['COVERAGE_DIR'],
'cov.%s' % random.randrange(0, 1000000000000))
cov = coverage.coverage(data_file=covpath, auto_data=True)
cov._warn_no_data = False
cov._warn_unimported_source = False
cov.start()
except ImportError:
pass