Run Coin, start a build, stop it while it's running.
Launch Coin again. Note that the state of the build will say that it's cancelled (good).
Now check the details of the integration, the individual work items (build/test) were not marked as cancelled and are still in running state.
The culprit is in src/scheduler.py. There is code to clean up on restart, but it only looks at the integration file, it should also iterate over all individual work items and mark their state as cancelled.