Function unblocked_in_child 

pub fn unblocked_in_child(command: &mut Command) -> &mut Command

Start command’s child with no signal blocked. While a guard is alive this thread blocks the signals that end proc, and a child inherits the mask (the standard library keeps it), so an lsof that watch runs on a refresh could not be stopped by Ctrl-C, SIGTERM, SIGHUP or SIGQUIT.