Bug 2434887

Summary: openblas: FTBFS - possible miscompilation on Power10 with GCC 16
Product: [Fedora] Fedora Reporter: Fedora Release Engineering <releng>
Component: gccAssignee: Jakub Jelinek <jakub>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: rawhideCC: aekoroglu, dan, dmalcolm, fweimer, jakub, jlaw, josmyers, jwakely, mcermak, mpolacek, msebor, nforro, nickc, nixuser, psimovec, sipoyare, susi.lehtola
Target Milestone: ---   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1071880, 2384424    
Attachments:
Description Flags
build.log
none
root.log
none
state.log none

Description Fedora Release Engineering 2026-01-29 05:12:17 UTC 
openblas failed to build from source in Fedora rawhide/f44

https://koji.fedoraproject.org/koji/taskinfo?taskID=141172676


For details on the mass rebuild see:

https://fedoraproject.org/wiki/Fedora_44_Mass_Rebuild
Please fix openblas at your earliest convenience and set the bug's status to
ASSIGNED when you start fixing it. If the bug remains in NEW state for 8 weeks,
openblas will be orphaned. Before branching of Fedora 45,
openblas will be retired, if it still fails to build.

For more details on the FTBFS policy, please visit:
https://docs.fedoraproject.org/en-US/fesco/Fails_to_build_from_source_Fails_to_install/
Comment 1 Fedora Release Engineering 2026-01-29 05:12:41 UTC 
Created attachment 2126409 [details]
build.log

file build.log too big, will only attach last 32768 bytes
Comment 2 Fedora Release Engineering 2026-01-29 05:12:46 UTC 
Created attachment 2126410 [details]
root.log

file root.log too big, will only attach last 32768 bytes
Comment 3 Fedora Release Engineering 2026-01-29 05:12:49 UTC 
Created attachment 2126411 [details]
state.log
Comment 4 Dan Horák 2026-03-19 16:46:21 UTC 
I can't reproduce the failure (test segfault) on Power9 based system, so perhaps this is hardware (Fedora builders are Power10) and/or compiler (GCC 16?) related.
Comment 5 Dan Horák 2026-03-27 12:39:46 UTC 
Newer upstream releases > 0.3.29 contain some Power10 fixes, so perhaps just rebasing to newer upstream release could make the test failure go away.
Comment 6 Dan Horák 2026-03-30 11:16:06 UTC 
My testing so far points to a combination of Power10 builder and GCC 16. Rebasing to newer upstream release won't (easily) help, because the new versions suffer from the same (0.3.30) or a different issue (0.3.31+).
Comment 7 Dan Horák 2026-03-31 14:55:28 UTC 
Hi Jakub, please see the upstream issue on Github for my investigation so far.
Comment 8 Jakub Jelinek 2026-04-07 16:58:23 UTC 
Bisected to kernel/power/sbgemv_t_power10.c (everything from libopenblass*.a -O0 and just that one built normally works) and latest bisected to https://gcc.gnu.org/r16-1782 change (unfortunately, it causes significant RA choices in several functions in that file).