Does it progress any further if the repo username and repo are correct? You said it was failing when attempting to clone the repo (which makes sense since the user was wrong).
Since you have the role_name and namespace defined in the meta/main.yml, I’d expect the real Github user/repo to be passed to ansible-galaxy. There’s a related post here on those features Ansible Galaxy’s role import enhancements and fixes for the new year.
Edit: by the way, I looked at the recent role import failures and I see a bunch of variations you’ve tried, but I don’t see any using eclipse-slm as the Github user, so it might be worth trying again.