This morning I've been plagued with scenarios like this when trying to
hack on gnulib:
$ git pull
Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
$ [wait for a while]
$ git pull
Already up-to-date.
$ [finally! Now I can push.
$ git push
Counting objects: 15, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (15/15), done.
Writing objects: 100% (15/15), 4.67 KiB | 0 bytes/s, done.
Total 15 (delta 13), reused 0 (delta 0)
[at this point execution waited for 40 minutes! Then:]
remote: 2016-02-19 18:16:27 Failed to get user name for uid 69712
[and execution continues to hang]
