[buildd-tools-devel] Bug#817236: schroot: no access to pseudo-terminals in new chroots

[Ansgar Burchardt]

On Wed, 2016-03-09 at 11:41 +0100, Marco d'Itri wrote:
> On Mar 09, Ansgar Burchardt <ansgar at debian.org> wrote:
> 
> > in the sbuild profile's fstab. To accommodate old chroots that
> > still
> > have a /dev/ptmx device node, an additional bind mount
> > 
> >   ${chroot}/dev/pts/ptmx   /dev/ptmx   none   rw,bind 0 0
> > 
> > is needed to make sure only the devpts' ptmx device is used. I
> > don't
> > think this can be done via the profile's fstab, but only via a
> > setup
> > script?
> No, a plain bind mount inside the chroot is needed and it can be 
> configured in fstab:
> 
> /dev/pts/ptmx   /dev/ptmx   none   bind 0 0

schroot's fstab differs from the regular fstab:

  The only difference is that the mountpoint path fs_dir is
  relative to the chroot, rather than the root.

An entry like

  /dev/pts/ptmx   /dev/ptmx   none   bind 0 0

thus bind-mounts /dev/pts/ptmx on ${chroot}/dev/ptmx, that is it would
mount the *host's* /dev/pts/ptmx on the chroot's /dev/ptmx. This should
not work.

There doesn't seem a way to specify also the first field relative to
the chroot, thus the likely requirement to handle this in a setup
script.

Ansgar