When trying to update the default branch after importing a repository, it will fail if the imported repository does not have a "master" branch (the default "default" branch for a newly created repository).
- Import a repository
- See the "refs/head/master does not exist" message on the Source view
- Navigate to repository settings
- Attempt to update the default branch
The default branch is updated.
Receive a "refs/heads/master is set as the default branch, but this branch does not exist"
- Create a "master" branch
- Update the default branch
- Delete the "master" branch