Hydra only fetches older commits from private Gitlab repo

I try to setup a build pipeline with a local hydra instance which I set up according to the wiki.

When fetching the flake, I use
as input.

I have all the keys and permissions set up and it works, hydra fetches the repo and I can see it in the hydra machines /nix/store under …-source.

Problem is, hydra does not fetch the newest commit, always the same old one.

I tried appending the commit hash with

but then it says “Host key verification failed”, which seems weird because hydra can fetch the repo but no individual commits?

I would love to get some guidance on how to proceed :pray:

Update: it works flawlessly when the repo is public.

I would really appreciate some help :slight_smile: