Bug#476810: Please clarify 12.5, "Copyright information"

[Russ Allbery <rra@debian.org>]

Matthias Klose <doko@cs.tu-berlin.de> writes:

> Package: debian-policy
> Version: 3.7.3.0
>
> 12.5 currently reads: "/usr/share/doc/package may be a symbolic link to
> another directory in /usr/share/doc only if the two packages both come
> from the same source and the first package Depends on the second. These
> rules are important because copyrights must be extractable by mechanical
> means."
>
> Proposing to clarify this to "... come from the same source and the
> first package directly or indirectly depends on the second ...". For the
> intention mentioned in the last sentence ("must be extractable by
> mechanical means") it doesn't matter if the dependency is direct or
> indirect. If there are other reasons for the stricter direct dependency,
> please clarify this as "directly depends".

I'm not sure that I see any need for a change here.  To resolve indirect
dependencies requires more of the logic of a package manager and may
require installing quite a large number of packages, whereas the current
requirement only requires one level of dependency handling.  Therefore,
the current requirement does indeed make copyrights more extractable by
mechanical means.

I'm also not sure what the motivation would be for relying on an indirect
dependency.  Doing so is generally strongly discouraged in Debian because
it's inherently fragile; it's too easy to change the downstream package's
dependencies without realizing the effect on upstream packages.

-- 
Russ Allbery (rra@debian.org)               <http://www.eyrie.org/~eagle/>