I have configured the GitHub Authentication module in line with the instructions (and tried rotating client secrets etc). It is set with new account creation _disabled_, but email addresses in GitHub match Hub accounts.
The OAuth flow is followed correctly, but upon granting access to the account in the GitHub UI, the redirect back to Hub replies with "Authentication Failed" every time. I'm guessing there is something missing in the configuration at one end or the other.
Has anyone experienced this and/or know of a workaround?