use FETCH_HEAD default for version_from_git
@@ -34,7 +34,7 @@ def pytest_addoption(parser):
"--report-path", action='store', dest='report_path', metavar='path', default='report.html',
help='create examples html report file at given path.')
parser.addoption(
- "--diff-ref", type=version_from_git, default="master@{upstream}",
+ "--diff-ref", type=version_from_git, default="FETCH_HEAD",
help="compare generated images against this ref")
parser.addoption(
"--incremental", action="store_true", default=False,
