[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Bug#206684: mandatory use of debconf for user prompting a release goal for squeeze



On Fri, Mar 20, 2009 at 09:13:19AM +1300, Andrew McMillan wrote:
> On Thu, 2009-03-19 at 10:55 -0700, Russ Allbery wrote:

> >     Packages that are essential or that are dependencies of essential
> >     packages may fall back on another prompting method if no such
> >     interface is available when they are executed.

> Since we're essentially saying that all packages must support debconf,
> why bother restricting the set of packages which are allowed to provide
> a fallback?

Because the fallback is a "worst case" scenario, because testing for files
on the filesystem is a poor proxy for determining whether the interface is
in a usable state, and because adding the fallback code means duplicating
logic in your maintainer script and making it way more complex than it needs
to be.  The fallback should only be permitted in Essential packages where it
has to be there in order to avoid unbreakable loops; in all other cases,
maintainers should properly declare their need for debconf and avoid making
their maintainer scripts more clever and less robust.

This also ensures that (assuming the maintainer is following policy) uses of
debconf in preinsts are publically vetted by debian-devel before hitting the
archive.

> From a maintainer's POV surely they will only be working to provide a
> fallback if they desire their package to be installable when debconf is
> not available.  I don't think we should second-guess their reasons for
> doing so.

On the contrary, the maintainer is already second-guessing the package
system and the normal rules governing maintainer scripts at that point.
While there may be cases we haven't thought of where a fallback is
necessary, I think we should be explicitly whitelisting these as they are
identified instead of leaving it to maintainers' individual judgement.

-- 
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@ubuntu.com                                     vorlon@debian.org



Reply to: