Using Docker executor with image ruby:2.1 ... Pulling docker image ruby:2.1 ... Running on runner-30dcea4b-project-1291597-concurrent-0 via runner-30dcea4b-machine-1468533452-7277b5d6-digital-ocean-4gb... Cloning repository for mentioned-user-tooltip with git depth set to 20... Cloning into '/builds/winniehell/gitlab-ce'... Checking out 30481cd2 as mentioned-user-tooltip... fatal: reference is not a tree: 30481cd24e43184643ac17e3dc13474419f52827
