ERROR: Job failed (system failure): unable to upgrade to tcp, received 500 (exec.go:71:0s)

Upgrading from 15.10.1 to 15.11.0 causes our local gitlab-runner instance to fail with the above error message. Downgrading to 15.10.1 fixes the issue for us again.

We're using podman as our runner via the docker executor.

If someone has a hint for me as to what to try configuration wise, I'd be thankful. Otherwise, I can give bisecting it a shot.