[2017/02/21 12:44:25.359] # If this is a scheduled build, we check for changes against the last scheduled commit.
[2017/02/21 12:44:25.360] if [ "" != "true" ]; then
[2017/02/21 12:44:25.360]   burn_in_args="--checkEvergreen"
[2017/02/21 12:44:25.360] fi
[2017/02/21 12:44:25.360] # Capture a list of new and modified tests.
[2017/02/21 12:44:25.360] python buildscripts/burn_in_tests.py --branch=master --buildVariant=enterprise-rhel-67-s390x --testListOutfile=jstests/new_tests.json --noExec $burn_in_args
[2017/02/21 12:45:18.267] Comparing current branch against None
[2017/02/21 12:45:18.267] Traceback (most recent call last):
[2017/02/21 12:45:18.267]   File "buildscripts/burn_in_tests.py", line 471, in <module>
[2017/02/21 12:45:18.267]     main()
[2017/02/21 12:45:18.267]   File "buildscripts/burn_in_tests.py", line 434, in main
[2017/02/21 12:45:18.268]     values.check_evergreen)
[2017/02/21 12:45:18.268]   File "buildscripts/burn_in_tests.py", line 207, in find_changed_tests
[2017/02/21 12:45:18.268]     revisions = callo(["git", "rev-list", base_commit + "..." + last_activated]).splitlines()
[2017/02/21 12:45:18.268] TypeError: cannot concatenate 'str' and 'NoneType' objects
[2017/02/21 12:45:18.292] Command failed: exit status 1
[2017/02/21 12:45:18.311] Task completed - FAILURE.