Authenticating with gitlab using golang/oauth2 fails.

Summary

Authenticating with gitlab using the golang/oauth2 client fails. GitLab.com needs to be added to the list of busted auth providers. See the discussion on the golang-nuts forum for more info.

Steps to reproduce

1. Setup a new gitlab application Settings -> Applications
2. Try to authenticate

Relevant logs and/or screenshots

When you try to authenticate using the golang/oauth2 client it fails with the following error:

Client authentication failed due to unknown client, no client authentication included, or unsupported authentication method.