gcc15: fix fasthadd and grpc for fc42/riscv64

[smuzaffar]

No description provided.

[smuzaffar]

please test

[cmsbuild]

A new Pull Request was created by @smuzaffar for branch IB/CMSSW_20_1_X/g15.

@akritkbehera, @iarspider, @raoatifshad, @smuzaffar can you please review it and eventually sign? Thanks.
@ftenchini, @mandrenguyen, @sextonkennedy you are the release manager for this.
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[cmsbuild]

cms-bot internal usage

[smuzaffar]

+externals

this should fix the riscv64 build failures for fasthadd and grpc

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IB/CMSSW_20_1_X/g15 IBs after it passes the integration tests. This pull request will now be reviewed by the release team before it's merged. @ftenchini, @mandrenguyen, @sextonkennedy (and backports should be raised in the release meeting by the corresponding L2)

[cmsbuild]

-1

Failed Tests: UnitTests
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-25bdac/55803/summary.html
COMMIT: 3f9eb1a
CMSSW: CMSSW_20_1_X_2026-09-08-2300/el9_amd64_gcc15
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10846/55803/install.sh to create a dev area with all the needed externals and cmssw changes.

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:

• @cms-sw [UBSAN] Apply abseil ubsan fix #10837

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-25bdac/55803/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-25bdac/55803/git-merge-result

Failed Unit Tests

I found 9 errors in the following unit tests:

---> test unitTestsGroup_1_u2 had ERRORS
---> test unitTestsGroup_4_u20 had ERRORS
---> test TestFWCoreIntegrationStandalone had ERRORS
and more ...

Comparison Summary

Summary:

• You potentially added 278 lines to the logs
• Reco comparison results: 73500 differences found in the comparisons
• DQMHistoTests: Total files compared: 45
• DQMHistoTests: Total histograms compared: 3592269
• DQMHistoTests: Total failures: 452674
• DQMHistoTests: Total nulls: 423
• DQMHistoTests: Total successes: 3139154
• DQMHistoTests: Total skipped: 18
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -0.05900000000000001 KiB( 44 files compared)
• DQMHistoSizes: changed ( 2023.0020001,... ): -0.012 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0000001,... ): -0.020 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0010001 ): 0.004 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0030001 ): 0.008 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0050001 ): -0.023 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0060001 ): 0.020 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0070001 ): -0.004 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2025.0000002 ): -0.027 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2025.0010001 ): 0.027 KiB JetMET/SUSYDQM
• Checked 195 log files, 163 edm output root files, 45 DQM output files
• TriggerResults: found differences in 13 / 44 workflows