Coincidentally, the IA tool of Semgrep just signalled me a real although very minor issue on some C project a couple of days ago. So I tried gecko on the same repository to see if it could detect anything else, but no. So I removed the fix from the github repo to see if gecko would also complain about the issue, but I believe I hit a bug in the UI: I deleted the previous project and created a new one, using the same github URL of course, and although gecko said that it started the scan, the list of scans stayed disapointingly empty.