How to troubleshoot a playground run - the debugging toolbox (Play Debug Console, labctl, examinerctl), scenario-by-scenario advice, and the labctl playground machine reference.
The tools for inspecting a playground run - the Play Debug Console (play spec, boot conditions, serial console logs, task details), the labctl commands, and examinerctl inside the VM.
Where to start depending on what is broken - a misbehaving service, failing init tasks, a run that doesn't boot, an unreachable or unresponsive run, or a run that is gone.
The per-machine labctl commands in detail - console (serial boot logs), journal (systemd journal streaming), reboot, stop, and restart.