Indeed, runit does not run the service as a session leader by default. runsvdir runs every instance of runsv in a different session, but a runsv instance runs its service in the same session. The workaround, as Jonathan pointed out, is to add "setsid" (or "chpst -P") to your run script, in the command line that execs into your daemon.
Note that s6 runs the service as a session leader by default, precisely to avoid that minor annoyance. There is no benefit in running the supervisor processes in a different session from the scanner process, but there is benefit in running the services in their own session. -- Laurent
