[buildd-tools-devel] Bug#751733: Bug#751733: --location does not work with session names

[Roger Leigh]

On Mon, Jun 16, 2014 at 06:46:20AM +0200, Martin Pitt wrote:
> Package: schroot
> Version: 1.6.10-1
> 
> Hello,
> 
> I'm trying to find out the chroot directory of a particular session
> (for autopkgtest's schroot runner, FTR), but this doesn't work:
> 
> | $ schroot -b -c sid
> | sid-amd64-327bb347-fe31-4c6d-9e36-a90ae70c4fa2
> |
> | $ schroot --location -n sid-amd64-327bb347-fe31-4c6d-9e36-a90ae70c4fa2
> | E: --session-name is not permitted for the specified action
> | I: Run “schroot --help” to list usage example and all available options
> |
> | $ schroot --location -c sid-amd64-327bb347-fe31-4c6d-9e36-a90ae70c4fa2
> | E: sid-amd64-327bb347-fe31-4c6d-9e36-a90ae70c4fa2: Chroot not found

Might be a namespace issue.  Does adding a "session:" prefix help?
It might be defaulting to a "chroot:" prefix for this command, in
which case it can't find a session ID since it's not under that
prefix.

> As a workaround I'm using --all-sessions and grep for the line with
> the session ID, but that's a bit cumbersome:
> 
> | $ schroot --location --all-sessions
> | /var/lib/schroot/mount/sid-amd64-327bb347-fe31-4c6d-9e36-a90ae70c4fa2
> 
> This happens with both type=directory and an union-type, as well as
> with type=file.

I think we can improve this.  Historically, this option only
existed for compatibility with dchroot.  However, the existing
behaviour is suboptimal.  It only really makes sense for it to
work with one chroot at a time since the output makes little
sense otherwise.  And it only really makes sense for sessions
since there might not even be a location for some chroot
types (snapshots, block devices, loopback mounts etc.)

I'd suggest:
- making it work with a mandatory --chroot=$name parameter
- defaulting the prefix to session (for the -c arg above)
- maybe remove support for working with non-session
  prefixes entirely.  This doesn't work consistently with
  chroot/source prefixes, but it does work with sessions
  (both from chroots and source chroots).

Due to the behaviour break, I'm reluctant to change it for
1.6.x, but for 1.7.x it's a reasonable break for a new
major release.


Regards,
Roger

-- 
  .''`.  Roger Leigh
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