Creating a process group in `Fork_action` (?)

[smondet]

Would it make sense to (optionally) add calls to setpgid(0,0) before the execve?

I think that would allow for better use of signal to kill entire process groups.

https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpgid.html

[talex5]

Optional support would be good, yes.