Bug#824495: debian-policy: Source packages "can" declare relationships

[Ian Jackson <ijackson@chiark.greenend.org.uk>]

Russ Allbery writes ("Bug#824495: debian-policy: Source packages "can" declare relationships"):
> I feel pretty strongly here that Build-Conflicts is not a correct solution
> to this problem, and therefore I'm not happy about the idea of adding a
> Policy rule that would imply that it was.  The problem was that the
> package didn't tolerate having automake installed, and fixing *that* was
> the correct fix.  But this seems fairly subtle to try to turn into a
> general Policy rule.

How about:

  Package builds MAY be affected, sometimes adversely, by the
  installation of additional packages beyond the Build-Depends
  and build-essential, subject to the following rules:

    Nature of package          Effect            Permitted
                               on build output

    Installed by default       Any effect        MUST NOT
    with any Build-Depends

    Part of any reasonble      Additional        SHOULD NOT
    default install for         features
    development workstation
                               Build fails       SHOULD NOT,
			                         MUST Build-Conflict

                               Builds broken     MUST NOT
                               packages

    Other packages             Additional        MAY
                                features

                               Build fails       SHOULD NOT,
			                         MUST Build-Conflict

                               Builds broken     MUST NOT
                               packages

Or to put it another way:

 Package builds MAY be influenced by the presence in the build
 environment of additional packages, beyond the Build-Depends and
 build-essential.  However:

 Additional packages MUST NOT have any effect other than either:

   (i) a failure of the build, in which case the additional packages
   MUST be declared in Build-Conflicts); or

   (ii) output packages with additional features or functionality.
   Such additional features MAY imply additional functional runtime
   dependencies, which then SHOULD be represented in the output
   packages' metadata.  In this case the additional packages
   SHOULD NOT be declared in Build-Conflicts.

 Additionally, in any case: additional packages which are installed by
 default by apt when the build dependencies are installed MUST NOT
 have any significant effect.

 Any additional package which could reasonably form part of a default
 install for a development workstation SHOULD NOT have any significant
 effect.

Ian.


-- 
Ian Jackson <ijackson@chiark.greenend.org.uk>   These opinions are my own.

If I emailed you from an address @fyvzl.net or @evade.org.uk, that is
a private address which bypasses my fierce spamfilter.