[Debian-med-packaging] Bug#1120614: Proposed fix — update bundled Eigen to 3.4.0

[Trupti]

Hello,

Did you get a chance to look into this fix ?


On 2025-11-13 15:52, Trupti wrote:
> On 2025-11-13 15:27, Trupti wrote:
>> On 2025-11-13 14:56, Trupti wrote:
>>> Package: src:arb
>>> Version: 6.0.6-8
>>> Severity: serious
>>> Tags: ftbfs forky sid
>>> X-Debbugs-Cc: debian-powerpc at lists.debian.org
>>> User: debian-powerpc at lists.debian.org
>>> Usertags: ppc64el
>>> 
>>> 
>>> Dear maintainer,
>>> 
>>> arb FTBFS on ppc64el with below error:
>>> 
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h: In
>>> function 'typename Eigen::ei_packet_traits<T>::type
>>> Eigen::ei_pset1(const Scalar&) [with Scalar = float; typename
>>> ei_packet_traits<T>::type = __vector(4) float]':
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h:194:40:
>>> error: declaration does not declare anything [-fpermissive]
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h:194:3:
>>> error: expected primary-expression before 'float'
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h:195:3:
>>> error: 'af' was not declared in this scope
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h:196:18:
>>> error: invalid parameter combination for AltiVec intrinsic
>>> '__builtin_vec_ld'
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h: In
>>> function 'typename Eigen::ei_packet_traits<T>::type
>>> Eigen::ei_pset1(const Scalar&) [with Scalar = int; typename
>>> ei_packet_traits<T>::type = __vector(4) int]':
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h:203:38:
>>> error: declaration does not declare anything [-fpermissive]
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h:203:3:
>>> error: expected primary-expression before 'int'
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h:204:3:
>>> error: 'ai' was not declared in this scope
>>> ../HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h:205:18:
>>> error: invalid parameter combination for AltiVec intrinsic
>> 
>> 
>> Hello,
>> 
>> The ARB package FTBFS on ppc64el with GCC 14+ due to errors in the
>> Altivec code from the bundled Eigen (eigen-2.0.16).
>> The errors occur in
>> HEADERLIBS/eigen/Eigen/src/Core/arch/AltiVec/PacketMath.h. These
>> intrinsics are deprecated on little-endian PowerPC and now rejected by
>> modern GCC.
>> 
>> 
>> Upstream Eigen replaced these deprecated intrinsics with
>> endian-agnostic equivalents starting around version 3.3.9
>> Below is the commit of that change.
>> https://gitlab.com/libeigen/eigen/-/commit/1615a2799384a2964d01ba77fe98e3f6fcc412f4
>> 
>> ARB currently bundles an older Eigen (eigen-2.0.16) which predates 
>> those fixes.
>> 
>> 
>> Thanks,
>> Trupti.
> 
> 
> Hi,
> 
> I tested the build failure on ppc64el and confirmed it is caused by
> the outdated Eigen version(2.0.16) bundled in ARB.
> 
> Replacing the bundled Eigen with Eigen 3.4.0 resolves the issue.The
> updated version already includes endian-safe Altivec intrinsics that
> compile correctly on ppc64el.
> 
> I tested a fix by updating the bundled Eigen to version 3.4.0 and
> adjusting one source file (`RNACMA/Cma.cxx`) for Eigen3 API
> compatibility. The package now resolves the issue of Altivec code on
> ppc64el.
> 
> A proposed patch is attached for review.
> 
> Changes summary:
>   • Update HEADERLIBS/Makefile to unpack Eigen 3.4.0.
>   • Add HEADERLIBS/eigen to CC_INCLUDES in Makefile.
>   • Update RNACMA/Cma.cxx to match Eigen 3 API.
> 
> 
> Please review and consider applying this patch.
> 
> 
> 
> 
> 
> 
> Note :
> After resolving this issue also arb pacakge is FTBFS on ppc64el with
> different errors. Which will be taken care by  bug number (#1114476).
> 
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1114476 bug report.
> 
> 
> Thanks,
> Trupti.