test-manifest: create constant for empty manifest
For symmetry with manifest v2, once we add that, let's extract a
constant for the empty v1 manifest.
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