Bug 510419

Summary: FTBFS with Eigen 5
Product: [Applications] step Reporter: Antonio Rojas <arojas>
Component: generalAssignee: Steve Cossette <farchord>
Status: RESOLVED FIXED    
Severity: normal CC: farchord
Priority: NOR    
Version First Reported In: 25.08.1   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Step 25.11.80 build log on Fedora Rawhide

Description Antonio Rojas 2025-10-09 08:54:21 UTC
The 'IterationController' and 'constrained_cg' functions used in stepcore/constraintsolver.cc have been removed in https://gitlab.com/libeigen/eigen/-/commit/e256ad1823c2eddd6954241ddc99bfeb7bb29cb3
Comment 1 Steve Cossette 2025-11-06 01:54:59 UTC
I can confirm this is still an issue in 25..08.3
Comment 2 Albert Astals Cid 2025-11-26 15:08:01 UTC
Git commit 7f6cd1fbf5f631aa64e94512ff5531233f1a2ed1 by Albert Astals Cid.
Committed on 26/11/2025 at 15:02.
Pushed by aacid into branch 'master'.

Import two files from old eigen

They were removed because of being LGPL but we do not have a problem
with that

M  +2    -1    stepcore/constraintsolver.cc
A  +183  -0    stepcore/eigenconstrainedconjgrad.h     [License: LGPL]
A  +152  -0    stepcore/eigeniterationcontroller.h     [License: LGPL]

https://invent.kde.org/education/step/-/commit/7f6cd1fbf5f631aa64e94512ff5531233f1a2ed1
Comment 3 Albert Astals Cid 2025-11-26 15:31:00 UTC
Git commit c538000f21ad7dcea77e233d8d237fdead54751e by Albert Astals Cid.
Committed on 26/11/2025 at 15:30.
Pushed by aacid into branch 'release/25.12'.

Import two files from old eigen

They were removed because of being LGPL but we do not have a problem
with that
(cherry picked from commit 7f6cd1fbf5f631aa64e94512ff5531233f1a2ed1)

M  +2    -1    stepcore/constraintsolver.cc
A  +183  -0    stepcore/eigenconstrainedconjgrad.h     [License: LGPL]
A  +152  -0    stepcore/eigeniterationcontroller.h     [License: LGPL]

https://invent.kde.org/education/step/-/commit/c538000f21ad7dcea77e233d8d237fdead54751e
Comment 4 Steve Cossette 2025-11-27 01:53:38 UTC
Created attachment 187201 [details]
Step 25.11.80 build log on Fedora Rawhide

This is still an issue here on 25.11.80. First, the CMakeLists.txt still hard-requires Eigen3 (See: https://invent.kde.org/education/step/-/blob/release/25.12/CMakeLists.txt?ref_type=heads#L47)

And I tried manually patching the Eigen3 version requirement out, I still get a failed build. See attached build log.
Comment 5 Antonio Rojas 2025-11-27 07:51:18 UTC
The version constraint is removed in https://invent.kde.org/education/step/-/merge_requests/41

The build failure has nothing to do with eigen and is already fixed in https://invent.kde.org/education/step/-/commit/86dda2a4a9c78fd457f0355b659c2d2262c36dba
Comment 6 Steve Cossette 2025-11-27 12:55:35 UTC
(In reply to Antonio Rojas from comment #5)
> The version constraint is removed in
> https://invent.kde.org/education/step/-/merge_requests/41
> 
> The build failure has nothing to do with eigen and is already fixed in
> https://invent.kde.org/education/step/-/commit/
> 86dda2a4a9c78fd457f0355b659c2d2262c36dba

Ah, right.... I didn't know I needed 3 total patches, not just one. This seems to work now, thanks!