The LabKey Server project hasn't updated the enlistment in two years or so and the last status message says it last failed 5 months ago. Can you provide details on why the update has failed?
The error seen is "can't convert nil into String". I'm not 100% sure if this refers to a directory name (doubtful) or a commit message or other log artifact (maybe a committer name etc.) I need to consult a more senior programmer who can maybe shed light on this one. Will report back.