After GitLab migration, pipeline get stuck in pending state and can't be cancelled
Summary
My pipeline is stalled by builds in pending state although cancelled multiple times. It seems directly caused by the recent migration to 9.4.
Steps to reproduce
I had a merge in progess that what waiting the green build to be automatically applied. It got never applied although the build was tagged as green. So I cancelled it and restarted my merge operation.
Once the merge done, a new pipeline was triggered but after 15 min was still in pending state. No build were triggered. I looked at my Gitlab-CI agent and found the following error in the logs:
Checking GitLab compatibility... OK runner=7987eba4
WARNING: Checking for jobs... failed runner=c845dad1 status=couldn't execute POST against https://gitlab.com/api/v4/jobs/request: Post https://gitlab.com/api/v4/jobs/request: EOF
ERROR: Checking GitLab compatibility... not-compatible reason=GitLab Runner >= 9.0 can be used ONLY with GitLab CE/EE >= 9.0 result=500 runner=c845dad1 statusText=500 Server Error
FYI, my gitlab-runner version is very recent (a few days).
So I restarted my agent and some jobs started to run again.
But my pipeline got stuck again in pending mode. I tried several times to cancel my pipeline, but it has no effect. All the jobs are done or cancelled, but the overall status get stuck to pending.