GitLab is used only for code review, issue tracking and project management. Canonical locations for source code are still https://gitweb.torproject.org/ https://git.torproject.org/ and git-rw.torproject.org.
Leekspin should be taught to generate HS descriptors to help with fuzzing Tor's parsers. See e.g. #14847 (moved), #3523 (moved), #15554 (moved), #3522 (moved), etc., which all contain at least one person saying some variant of the phrase "untested because I don't have an HS desc".