There is a comment in etc/system_perf.yml that has inconsistent leading spaces. So when a user uncomments this helpful comment, they might burn over half an hour trying to figure out why the evergreen server is rejecting their yml file with this error:

Unexpected reply from server (500 Internal Server Error): 400 (Bad Request): getting patched project: load project error(s): unmarshalling parser project from YAML: invalid configuration file: yaml: line 23: did not find expected key