Can't create the pull request to ocaml/opam-repository

```
[-] Submitting
dune-release: [INFO] Parsing opam file melange-fetch.opam
[-] Preparing pull request to ocaml/opam-repository
dune-release: [ERROR] /tmp/opam-repository-test is not a valid Git repository.
```

versions 2.0.0 and 2.1.0

The --verbose didn't gave me more information