Hello,
On Tue, 29 Nov 2022, at 13:54, Helmut Grohne wrote:
> I think this is none of dpkg's business. It's much like shared library
> dependencies, python dependencies and lots of other kinds. The usual way
> to do this is to have some tool that generates a substitution variables
> and debian/control uses it.
>
> Let me sketch something realistic.
>
> The pkgconf binary package gains a new script dh_pkgconf. This should be
> run after dh_auto_install and dh_install. It goes through all
> per-package installation directories and collects all installed .pc
> files from the usual paths (usr/lib/pkgconfig,
> usr/lib/<triplet>/pkgconfig and usr/share/pkgconfig). Then it locates
> all direct Requires and Requires.private and looks up the corresponding
> .pc files in the directories mentioned above and looks up the owning
> packages using dpkg -S. It then issues a per-package substitution
> variable ${pkgconf:Depends} to debian/<package>.substvars containing the
> located packages. For convenience, pkgconf also provides a debhelper
> sequence and Provides: dh-sequence-pkgconf. To use this new
> functionality, e.g. cryptsetup would have to add the build dependency on
> the sequence and add ${pkgconf:Depends} to libcryptsetup-dev's Depends.
>
> Andrej, does that make sense to you?
>
> I was also briefly looking into implementing this. Iterating over the
> packages and the .pc files is relatively simple, but figuring the direct
> Requires and Requires.private seems non-trivial. pkgconf
> --print-requires-private performs a recursive search and that's not what
> we want here to allow dependencies to modify their Depends without
> affecting us. So it seems like we'd have to write a .pc file parser. Is
> that correct?
Sorry for taking so long to answer. Yes, this makes total sense. I’ve made a
prototype using a pure-Perl pkg-config parser here:
https://salsa.debian.org/debian/pkgconf/-/merge_requests/14/diffs
What do you think?
Thanks!
--
Cheers,
Andrej
