The code are wrapped due to us using line-length=79 before, but now some
of the code can easily fit in 88 chars.
The formatter did not change this automatically when we changed line-length,
because of magic trailing commas that gets added when they turn into multiple lines.
Black/ruff wrapping them in parens and splitting them into multiple lines
was making it difficult to read.
fix: #8612
For checkpoint experiment in some case users might want to give it a early
stopping to reduce variance. But currently if we interrupt/kill the
experiment it will be marked as failed, and all of the completed
checkpoints will be removed as we cleanup all the running directly after
the process failed.
1. We raise CheckpointKilledError intead of StageCmdFailed error if at
least one checkpoint had been commited.
2. Temp_dir executor will continue collecting data if the Checkpoint
stage was interrupted.
3. Raise warnings if a checkpoint stage was incomplete and the other
stages were not forwarded.
4. Add a new functional test for this
* re-enable --jobs concurrency
* use `start_workers` instead of `spawn_worker`
* make `spawn_worker` a private method.
* update tests: make `spawn_worker` a private method.
1. Move some basic test script from function tests to unit test.
2. Add success/failed tests for the status change of `tempdir`, `celery`, `workspace` running case.