[git-buildpackage] Quilt patches get applied twice during gbp buildpackage

[Guido Günther]

Hi Markus,
On Fri, Nov 11, 2016 at 01:52:33PM +0100, Markus Blatt wrote:
> Hi Guido,
> 
> thanks for the fast reply.
> 
> On Fri, Nov 11, 2016 at 07:45:28AM +0100, Guido Günther wrote:
> > On Thu, Nov 10, 2016 at 10:23:32AM +0100, Markus Blatt wrote:
> > > 
> > > I have playing around with git-buildpackage for a few days (Debian
> > > stable). I am using the "3.0 (quilt)" source format (switched from
> > > 1.0) and like to quilt patches with a patch-queue branch. I can
> > > sucessfully build the packge on the patch-queue. But when I use the
> > > debian branch with the quilt patches they seem to get applied twice.
> > > This fails miserably.
> > > 
> > > The output of "gbp buildpackage --git-pristine-tar \
> > > --git-pristine-tar-commit -uc --git-verbose \
> > > --git-debian-branch=debian/sid"
> > > is attached.
> > > 
> > > Any ideas what goes wrong or how I could prevent one application of
> > > the quilt packages would be highly appreciated.
> > 
> > Please provide a git tree you run the above commands on and let me know
> > which branch you run tht on to reproduce this.
> > 
> 
> I have push the tags, debian/sid (failing build), and pristine-tar branches to
> https://github.com/blattms/ert-debian.git. The upstream is
> https://github.com/Ensembles/ert

Thanks. I think I see what the problem is:

debian/patches (and the corresponding patch-queue branch) only contains
changes to the upstream source, so it would never touch anything in
debian/. Changes to the debian packaging are done on the debian branch
(debian/sid in your case). Otherwise dpkg-buildpackage (which gets
invoked by git-buildpackage) would apply the patches to the already
existing dir during the unpack phase which gives the failure you're
seeing so the failure exists with and without using git-buildpackage.
I wonder if "gbp pq" should always filter out changes to debian/ to
avoid this kind of problems.

To show how this should look like I've moved the Debian changes to the
Debian branch while leaving the upstream changes in debian/patches, see

     https://github.com/agx/ert-debian

or 

     https://github.com/blattms/ert-debian/pull/1

Hope that helps,
 -- Guido