how to configure default branch name for `dune-release opam submit` with a custom repo?

[mbarbin]

I'm trying to submit an opam package to a custom repo using the --opam-repo option of dune-release opam submit (great that this exists btw!).

It fails when trying to pull, I believe due to it looking for the default branch named master - mine is called main.

error log

[-] Fetching https://github.com/mbarbin/opam-repository.git#master
   [in ../opam-repository/mbarbin]
=> exec:
     git --git-dir .git fetch https://github.com/mbarbin/opam-repository.git   master
dune-release: [ERROR] Exit code 128 from command
    `git --git-dir .git fetch https://github.com/mbarbin/opam-repository.git
       master`:
  fatal: couldn't find remote ref master

Is there a way to configure this name to be main rather than master?

Thanks!