New user here. When starting work on a project that uses main as the main branch name, there is no help or fallback for this error:
$ git appraise request
fatal: 'refs/heads/master' - not a valid ref
I had to read the code to figure out that -target is the needed option, but, that should really be a fallback mechanism, or, alternatively, the error comment should tell me that if I want this by default, I can do this through a specified (full example as best as possible) git config command to make this the default for this repo.