Recent failure to push a PR to GitLab

[Zimmi48]

It seems that there is a pre-receive hook at gitlab.com/coq/coq (probably a default pre-receive hook) that failed because of some internal error and prevented to push a PR to GitLab. Relevant logs:

2018-05-07T15:52:44.307834+00:00 app[web.1]: From https://github.com/Zimmi48/coq
2018-05-07T15:52:44.307856+00:00 app[web.1]:  * branch            clean-up/internal-function -> FETCH_HEAD
2018-05-07T15:52:45.757916+00:00 app[web.1]: remote: hooks/pre-receive:19:in `increase_reference_counter': undefined method `[]' for nil:NilClass (NoMethodError)        
2018-05-07T15:52:45.757933+00:00 app[web.1]: remote: 	from hooks/pre-receive:32:in `<main>'        
2018-05-07T15:52:45.776715+00:00 app[web.1]: To git@gitlab.com:coq/coq
2018-05-07T15:52:45.776723+00:00 app[web.1]:  ! [remote rejected] 40c97a2c23e7f6c49b8812346c2e05190ed6f496 -> pr-7450 (pre-receive hook declined)
2018-05-07T15:52:45.776726+00:00 app[web.1]: error: failed to push some refs to 'git@gitlab.com:coq/coq'
2018-05-07T15:52:45.778633+00:00 app[web.1]: Command "cd ~/repo && GIT_SSH_COMMAND='ssh -i ~/bot_rsa -o "StrictHostKeyChecking=no"' git fetch https://github.com/Zimmi48/coq clean-up/internal-function && cd ~/repo && GIT_SSH_COMMAND='ssh -i ~/bot_rsa -o "StrictHostKeyChecking=no"' git push git@gitlab.com:coq/coq +40c97a2c23e7f6c49b8812346c2e05190ed6f496:refs/heads/pr-7450" exited with status 1.

To investigate and maybe open a bug report at GitLab.

[Zimmi48]

I haven't seen any recent similar occurrences.