return exit code from exec_command()

[akvadrako]

I would like to check that my commands succeed from my calling script. This small change allows that to happen.

[aanand]

This looks alright as a default. It adds another API call to exec_command, but people can always avoid that by using the lower-level ExecOperation interface.

LGTM

[TomasTomecek]

nicely done

looks like that SimpleQueue has different defintions on 2 and 3:

2

Init definition: SimpleQueue(self)

3

Init definition: SimpleQueue(self, *, ctx)