On Thu, 2009-03-19 at 13:59 -0700, Steve Langasek wrote:
> 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.
OK, those are excellent reasons.
Here's an updated patch to apply the following wording:
Package maintainer scripts may prompt the user if necessary.
Prompting must be done by communicating through a program, such
as debconf, which conforms to the Debian Configuration
Management Specification, version 2 or higher.
Packages which are essential, or which are dependencies of
essential packages, may fall back on another prompting method if
no such interface is available when they are executed.
Cheers,
Andrew.
------------------------------------------------------------------------
andrew (AT) morphoss (DOT) com +64(272)DEBIAN
Flexibility is overrated. Constraints are liberating.
------------------------------------------------------------------------
diff --git a/policy.sgml b/policy.sgml
index df586d1..8f02c12 100644
--- a/policy.sgml
+++ b/policy.sgml
@@ -1218,17 +1218,16 @@
<heading>Prompting in maintainer scripts</heading>
<p>
Package maintainer scripts may prompt the user if
- necessary. Prompting should be done by communicating
+ necessary. Prompting must be done by communicating
through a program, such as <prgn>debconf</prgn>, which
conforms to the Debian Configuration Management
- Specification, version 2 or higher. Prompting the user by
- other means, such as by hand<footnote>
- From the Jargon file: by hand 2. By extension,
- writing code which does something in an explicit or
- low-level way for which a presupplied library
- (<em>debconf, in this instance</em>) routine ought
- to have been available.
- </footnote>, is now deprecated.
+ Specification, version 2 or higher.
+ </p>
+
+ <p>
+ Packages which are essential, or which are dependencies of
+ essential packages, may fall back on another prompting method
+ if no such interface is available when they are executed.
</p>
<p>
