[debhelper-devel] Bug#839681: debhelper: autoconf buildsystem: regression due to cross compilation improvements in makefile buildsystem

[Helmut Grohne]

Package: debhelper
Version: 10.2.1
User: helmutg at debian.org
Usertags: rebootstrap

Hi Niels,

thank you for applying an improved version of my patch in #836988.
Unfortunately, it doesn't quite work as expected. The intention was that
our modification to the makefile buildsystem wouldn't affect packages
that were using other buildsystems (e.g. autoconf). Unfortunately, the
buildsystem is not a per-source package property. Instead, it is a
per-target property. The autoconf buildsystem currently only handles
configure and test and defers all other targets to the makefile
buildsystem. That happens to include the build target, which we changed.

This is very unfortunate as it happens to break cross building icu,
which needs to do a native build before doing the actual cross build.
I'd also expect it to break other packages, so we'll probably need to
change the behaviour again.

I basically see two possible solutions:

 * Acknowledge that changing the makefile buildsystem also changes
   dh_auto_build for autoconf packages and thus the original change
   needs to be reverted.
 * Ensure that child classes of makefile.pm take all targets.

I am attaching a patch for the latter (as revert is trivial). I think
the change conceptually makes sense, because using different
buildsystems was unexpected to me (and Paul Wise). I also checked all
other child classes and all of them (including mkcmake) do take over all
targets. This might actually be a regression introduced in commit
758ce0bb1fbb505aa05f2dd3ac85d7d084b94312.

Indeed the icu build is fixed both by applying this patch and by adding
--buildsystem=autoconf to dh_auto_build. I don't consider the latter a
proper fix, because it is too counter-intuitive that this should be
necessary and because it likely breaks other packages as well.

What do you think? If all else fails, I vote for revert.

Helmut
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-fix-autoconf-cross-regression-from-836988.patch
Type: text/x-diff
Size: 2172 bytes
Desc: not available
URL: <http://lists.alioth.debian.org/pipermail/debhelper-devel/attachments/20161003/40cdf699/attachment-0001.patch>