Bug#887482: xorg-server: FTBFS: dh_autoreconf can only be run once

[Niels Thykier <niels@thykier.net>]

Sven Joachim:
> On 2018-01-17 00:40 -0800, Daniel Schepler wrote:
> 
>> Source: xorg-server
>> Version: 2:1.19.5-1
>> Severity: serious
>>
>> From my pbuilder build log:
>>
>> [...]
>>
>> On further testing, it seems that on a freshly unpacked source, either
>> "dpkg-buildpackage -B" or "dpkg-buildpackage -A" separately will work;
>> but "dpkg-buildpackage -b" will fail with the above error.
> 
> This seems to have been triggered by the sequence handling rewrite in
> debhelper 11.1, at least I was not able to reproduce it anymore after
> downgrading debhelper to version 11.
> 
> In debhelper 11, the sequence of commands dh runs is this:
> 
> [...]
> 
> Whereas in 11.1.2 dh runs the following sequence:
> 
> [...]
> 
> This causes dh_autoreconf to be run twice, first via the build-indep
> rule and then as part of the standard dh sequence.  Some advice from the
> debhelper maintainer (CC'ed) would be appreciated.
> 
> Cheers,
>        Sven
> 

Hi,

This is a side-effect of fixing #880840.  I do not have a good generic
solution to this issue out of the box.  Even if I roll it back and guard
it by a compat level, we are just postponing your problem.

  I am open to suggestions.

Thanks,
~Niels

Re: #880840:

That bug shows that debhelper would happy inline "build-arch" +
"build-indep" even if the build target was defined and *afterwards* call
the build target - effectively building packages twice as well.
  Via base-files, we learned that the bug also meant that debhelper was
not keeping its promise of running make targets when they were defined
(#886901 comment 35).

The current behaviour is probably the closest debhelper has been at
doing sequences "correctly", "sanely" and as the documentation implies
it would.  Sadly, we are not done with feature interactions as you have
observed (with dh_autoreconf's limitation showing up in your build).