install hangs on private repo while checking manifests

[tasador]

librarian-puppet (2.2.1) hangs while checking out a private git repo. This is not a general problem, because other private and public repos work. Only a specific git repo with over 1750 branches seems to hang on checking out the module:

[Librarian] Resolving MODULE-name (>= 0) <repo#branch(directory)>
[Librarian] Checking manifests
[Librarian] --- No output
[Librarian] --- No output
[Librarian] --- No output
[Librarian] --- No output
[Librarian] --- No output
[Librarian] --> origin

(I cleared any specifics from the above output). Could I be hittng some kind of limit? It worked before with this repo, but new branches were being added continuously. I can clone the branch with git, so basically that repo works. It hangs for over an hour, then I interrupted.