Re: s6-svscan does not terminate after SIGTERM under amd64 (Docker) qemulation

From: Saj Goonatilleke <>
Date: Mon, 7 Feb 2022 16:21:33 +1100

On 4/2/2022 23:00, Laurent Bercot wrote:
>  So, SIGTERM does nothing because posix_spawn() is lying to s6-svscan,
> pretending to have succeeded when it doesn't know it yet (and is going
> to fail), and goading it into not doing anything. And it's lying
> because something in qemu is messing with the semantics of CLONE_VFORK.

Amazing. Thank you, Laurent! It probably would have taken me a while
to turn my suspicions on such a crucial library function.

For any future s6 users who happen to stumble upon this thread in an
archive search, the upstream qemu bug appears to be here:

>  I'm sorry, but I don't have an easy solution for you

No problem at all. Given the proximate cause, I can avoid the fault
without too much trouble.

Sometimes, the little devil on my shoulder yelling 'that is not right'
makes it hard to ignore even the most practically insignificant bugs.
(Not that posix_spawn() is, in any way, insignificant, but we do not use
qemu in production.) Your comprehensive reply help put my mind at ease.

Thanks again -- for this, and for s6.
Received on Mon Feb 07 2022 - 06:21:33 CET

This archive was generated by hypermail 2.4.0 : Mon Feb 07 2022 - 06:22:10 CET