Some builds are stuck at git-fetch and cause job execution timeout

Problem

During Merge Train Evaluation on www-gitlab-com, we observed that sometimes a pipeline job hung until it's failed by timeout. Since the current timeout is set to 1 hour, the merge train cannot proceed merges for the period, thus the queues will be snowballed.

The root cause is that the getting repository in script (git-fetch) takes a long time (or stuck). https://gitlab.slack.com/archives/CHLKE258E/p1583324816042500. This seems infra issue, and not Merge Train issue.

Examples of timeout failures:

Proposal

Reduce the job time out setting to 30 minutes from 1 hour. This allows Merge Train to quickly abandon a stuck pipeline and move on to the next queue. => This is not valid that review-stop takes almost an hour.

/cc @ogolowinski @csouthard

Edited by Shinya Maeda