Propagate SIGINFO to all processes

[joeytepp]

NOTE: This only works on MacOS since there is no SIGINFO signal on Linux. See golang/go#1653

My team has been using overmind for a while now and 1 thing that's been missing for us has been the propagation of the SIGINFO signal. One of our processes traps SIGINFOs (through ctrl + t) when run in isolation, however when using overmind this no longer works. This change would propagate the SIGINFO signal to all overmind processes which would allow for each process to handle the signal itself.

You could test locally this by creating the following Procfile at the root of your folder

test: sleep 10000

and then running go build && ./overmind start. After this press ctrl + t to trigger info and verify that you get the output of the SIGINFO signal on the sleep process. It should look something like

load: 8.65  cmd: tmux 59513 waiting 0.00u 0.00s
test   | sleep: about 9998 second(s) left out of the original 10000

[joeytepp]

@DarthSim would greatly appreciate a review on this when you have the time 🙏

[iyaz-shaikh]

LGTM!

[joeytepp]

Had to do this since syscall.SIGINFO isn't defined in go on Linux, see golang/go#1653

[joeytepp]

The alternative would be to create separate files with build tags for linux and darwin, but this seemed like a much simpler approach

[DarthSim]

Hey @joeytepp!
This looks nice, thanks for your contribution!