https://www.githubstatus.com/incidents/t2xwk9mz56f4 should be the URL
I'm seeing 500s when accessing any repo while logged in.
requests using the "_gh_sess" cookie are failing. If you can remove that cookie, request will work. Of course that means you cant make any authenticated requests, but its a workaround.
Looks like a larger one than usual: https://www.githubstatus.com/incidents/t2xwk9mz56f4