Bug#1057050: qt6-multimedia: Please build with EIGEN_DONT_VECTORIZE on powerpc to fix FTBFS

[John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>]

Hello,

On Sun, 2024-06-09 at 16:39 +0200, marillat wrote:
> > This can be fixed by switching off vectorization in the »eigen« using the preprocessor
> > macro EIGEN_DONT_VECTORIZE which can be defined on the cmake command line using the
> > cmake variable COMPILE_DEFINITIONS:
> > 
> > --- qt6-multimedia-6.4.2/debian/rules.orig      2023-07-26 17:52:13.000000000 +0200
> > +++ qt6-multimedia-6.4.2/debian/rules   2023-11-28 18:26:47.950137854 +0100
> > @@ -9,6 +9,10 @@
> >         cmake_extra_args += -DQT_HOST_PATH=/usr
> >  endif
> >  
> > +ifneq (,$(filter $(DEB_HOST_ARCH),powerpc))
> > +       cmake_extra_args += -DCOMPILE_DEFINITIONS="EIGEN_DONT_VECTORIZE"
> > +endif
> > +
> >  %:
> >         dh $@ --with pkgkde_symbolshelper --buildsystem=cmake+ninja
> >  
> > With the above change, cmake defines the preprocessor macro EIGEN_DONT_VECTORIZE and
> > the build succeeds on powerpc.
> 
> With qt6-multimedia 6.6.2 qt6-multimedia still fail to build even with
> this patch.
> 
> I'm unable to find a solution. Adrian do you have an idea ?

The syntax of my proposed solution was wrong. My local tests were not performed
on a clean source which is why I did not notice the suggested syntax didn't work.

The proper syntax is:

ifneq (,$(filter $(DEB_HOST_ARCH),powerpc))
        export DEB_CXXFLAGS_MAINT_APPEND = -DEIGEN_DONT_VECTORIZE
endif

@Patrick: Could you update the debian/rules file please to use the above syntax?

Thanks,
Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913