Bug 2434887 - openblas: FTBFS - possible miscompilation on Power10 with GCC 16
Summary: openblas: FTBFS - possible miscompilation on Power10 with GCC 16
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: gcc
Version: rawhide
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Jakub Jelinek
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks: PPCTracker F44FTBFS
TreeView+ depends on / blocked
 
Reported: 2026-01-29 05:12 UTC by Fedora Release Engineering
Modified: 2026-04-07 18:25 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: ---
Embargoed:


Attachments (Terms of Use)
build.log (32.00 KB, text/plain)
2026-01-29 05:12 UTC, Fedora Release Engineering
no flags Details
root.log (32.00 KB, text/plain)
2026-01-29 05:12 UTC, Fedora Release Engineering
no flags Details
state.log (1.64 KB, text/plain)
2026-01-29 05:12 UTC, Fedora Release Engineering
no flags Details


Links
System ID Private Priority Status Summary Last Updated
GNU Compiler Collection 124804 0 P1 UNCONFIRMED [16 Regression] Possible openblas miscompilation since r16-1782 2026-04-07 18:25:45 UTC
Github OpenMathLib OpenBLAS issues 5728 0 None open test failures with POWER10 kernel and GCC 16 2026-03-31 08:07:42 UTC

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).


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