When I try to push to master I get:
remote: fatal error in commit_refs
How can I solve this?
From my experience, there is now (2019) some rate limit on GitHub that causes this problem for me when mass-pushing tens of huge repositories. It can also cause "cannot read" problem in random cases.
When I delay for 30 seconds before each push, both problems go away and I can continue with hundreds of repos without a glitch (sigh, don't even ask).