Error: repository not found / Preferred way to deal with multiple git identities

[MartyLake]

Hello.
I need to manage multiple git identities on the same computer. For the vanilla git tool, and any tool that calls git, I can use env variables GIT_SSH_COMMAND, GIT_AUTHOR_EMAIL GIT_AUTHOR_NAME GIT_COMMITTER_EMAIL GIT_COMMITTER_NAME and adding/removing keys to ssh-agent accordingly.
However, for git-bug, I have an error which I suspect comes from that situation:

$ git pull
Everything up-to-date
$ git bug pull
Fetching remote ...
Error: repository not found

Do you have an idea of the reason of the issue?
Best,