"ValueError: signal only works in main thread" with external_program.py

[heimalne]

We're running Luigi on a non-main thread and encountered another signal error problem when using ExternalProgramTask:
That task tries to register a signal handler, which crashes Luigi, because it's not on the main thread:

luigi/luigi/contrib/external_program.py

Line 217 in 3de0560

signal.signal(signal.SIGTERM, self.kill_job)

For workers, the following config flag for luigi.cfg was introduced as a workaround:

[worker]
no_install_shutdown_handler=True

See

luigi/luigi/worker.py

Lines 336 to 338 in 64d6b83

	no_install_shutdown_handler = BoolParameter(default=False,
	description='If true, the SIGUSR1 shutdown handler will'
	'NOT be install on the worker')

Would a similar workaround make sense in this case as well?