[buildd-tools-devel] re buildd's resolver and package's build deps
Steve Langasek
vorlon at debian.org
Mon Feb 28 20:23:19 UTC 2011
On Mon, Feb 28, 2011 at 07:12:00PM +0000, Roger Leigh wrote:
> This was a pain when we changed the default inetd--every package
> required updating. For others, e.g. mail-transport-agent, it's even
> more painful (I thought an mta-default was proposed, similar to
> virtual-policy above, but can't see it in use yet).
$ apt-cache showpkg default-mta
Package: default-mta
Versions:
Reverse Depends:
uw-imapd,default-mta
ipopd,default-mta
smartlist,default-mta
psad,default-mta
procmail,default-mta
mutt,default-mta
python-moinmoin,default-mta
mdadm,default-mta
mailutils,default-mta
logcheck,default-mta
inn,default-mta
fwknop-server,default-mta
fetchmail,default-mta
drupal6,default-mta
darcs,default-mta
capisuite,default-mta
bsd-mailx,default-mta
backuppc,default-mta
anacron,default-mta
Dependencies:
Provides:
Reverse Provides:
exim4-daemon-light 4.72-6
$
There are still a number of packages that declare a preferred mta explicitly
- including some that declare a different preference than the Debian one! -
but by and large these packages don't seem to be bothering anybody yet.
> If we had a centralised list (apt could use them during resolving
> directly), or a set of dummy default packages (as virtual-policy), a
> package could depend upon just the virtual package, and this would allow
> the default to be changed in a single place, pain free.
I think that's a topic to be discussed with the apt maintainers. One of the
ideas brought up when default-mta was implemented was for apt to sort by
package priority for considering solutions to virtual packages, but it
didn't appear anyone was willing to implement it.
I don't think this is going to be as generally useful as you suppose,
however. default-mta was the only case where this issue has ever risen to
the level of warranting discussion on debian-devel, and it's already been
addressed. More commonly, we have:
- some virtual packages we really don't care which real package provides
- some virtual packages for which there is no one correct default because
different reverse-deps legitimately have different preferences
- some virtual packages for which there is one obvious,
persistently-correct default, so this doesn't buy us anything but a new
transition
So I guess the challenge is to get anyone to care enough to implement it.
(Maybe this could make a reasonable GSoC project?)
--
Steve Langasek Give me a lever long enough and a Free OS
Debian Developer to set it on, and I can move the world.
Ubuntu Developer http://www.debian.org/
slangasek at ubuntu.com vorlon at debian.org
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 828 bytes
Desc: Digital signature
URL: <http://lists.alioth.debian.org/pipermail/buildd-tools-devel/attachments/20110228/77556925/attachment.pgp>
More information about the Buildd-tools-devel
mailing list