For starters, one way to silence the warning (since threads 1.33?) is to detach the threads.

All very well if you *never* need to join the threads, but if, for example, you normally want to join them (to retrieve their results), but want to be able to terminate the process quickly without waiting for them if you receive a SIGTERM, you're stuffed.

You can't even use the costly and nearly useless $thr->kill( <SIG> ) mechanism to pass on the signal, because it won't interupt IO, sort, etc. So, you're forced to either:

• enable unsafe signals and risk crashing the entire process when you signal a thread.

• use event-driven techniques--non-blocking IO; breaking code into iddy-biddy chunks--to ensure that your threads are periodically in a position to receive the signals.

  In which case you might as well just check a shared flag.

• use _exit()

  Whilst it has risks, they are mostly mitigatable, and at least you control when things happen.

These messages are entirely configurable and should be user controllable. Just another case of module authors deciding that they know better than module users.

If you wish to run your program in the background, ...

Where did that come from? Are you party to information not in the OP?