CI job scripts do not complete when dockerd or any process runs in the background

Summary

script never finishes when dockerd was started in background. Possibly the same with any kind of process running in the background.

Steps to reproduce

Start dockerd process in before_script, then run any kind of script.

Actual behavior

all commands in script finish, but the build hangs indefinitely.

Expected behavior

the script should finish. Remaining background processes probably shouldn't get touched. They will be cleaned up by terminating the build VM/container or simply the parent process exiting.

Environment description

gitlab.com with kubernetes executor.

Used GitLab Runner version

Running with gitlab-runner 10.1.0 (c1ecf97f) on Kubernetes Runner (4ff78e82)

Workarounds

• double fork the background process
• kill the background process before exiting the job