Do not use -Ofast in libxz

[fwyzard]

No description provided.

[fwyzard]

please test

[cmsbuild]

A new Pull Request was created by @fwyzard for branch IB/CMSSW_16_1_X/master.

@akritkbehera, @iarspider, @raoatifshad, @smuzaffar can you please review it and eventually sign? Thanks.
@ftenchini, @mandrenguyen, @sextonkennedy you are the release manager for this.
cms-bot commands are listed here

[cmsbuild]

cms-bot internal usage

[cmsbuild]

-1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7a57f6/50534/summary.html
COMMIT: cce7e6a
CMSSW: CMSSW_16_1_X_2026-01-12-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10273/50534/install.sh to create a dev area with all the needed externals and cmssw changes.

Failed External Build

I found compilation warning when building: See details on the summary page.

[fwyzard]

please test

what ?

[cmsbuild]

-1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7a57f6/50540/summary.html
COMMIT: cce7e6a
CMSSW: CMSSW_16_1_X_2026-01-12-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10273/50540/install.sh to create a dev area with all the needed externals and cmssw changes.

Failed External Build

I found compilation warning when building: See details on the summary page.

[fwyzard]

please test

[cmsbuild]

-1

Failed Tests: RelVals
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7a57f6/50591/summary.html
COMMIT: cce7e6a
CMSSW: CMSSW_16_1_X_2026-01-13-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10273/50591/install.sh to create a dev area with all the needed externals and cmssw changes.

Failed RelVals

• 34634.999

----- Begin Fatal Exception 14-Jan-2026 03:48:58 CET-----------------------
An exception of category 'OutOfBound' occurred while
   [0] Processing  Event run: 1 lumi: 1 event: 4 stream: 0
   [1] Running path 'HLTriggerFinalPath'
   [2] Prefetching for module TriggerSummaryProducerAOD/'hltTriggerSummaryAOD'
   [3] Prefetching for module L1HPSPFTauProducer/'l1tHPSPFTauProducer'
   [4] Prefetching for module L1TPFCandMultiMerger/'l1tLayer1'
   [5] Prefetching for module L1TCorrelatorLayer1Producer/'l1tLayer1HGCal'
   [6] Calling method for module HGCalBackendLayer2Producer/'l1tHGCalBackEndLayer2Producer'
Exception Message:
TC X1 = 0.0713466 out of the seeding histogram bounds 0.076 - 0.58
----- End Fatal Exception -------------------------------------------------

[cmsbuild]

Pull request #10273 was updated.

[fwyzard]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7a57f6/51487/summary.html
COMMIT: a9cd3c0
CMSSW: CMSSW_16_1_X_2026-02-20-2300/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmsdist/10273/51487/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 12 lines to the logs
• Reco comparison results: 13 differences found in the comparisons
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4172102
• DQMHistoTests: Total failures: 76
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4172006
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 52 files compared)
• Checked 227 log files, 198 edm output root files, 53 DQM output files
• TriggerResults: no differences found

[mandrenguyen]

+1
As long as it passes tests, I trust that you have a good reason for making this change. For reference would you please explain in the PR description why it's preferable to run without this flag for this particular library? I leave it for @cms-sw/externals-l2 to merge whenever they are happy.

[fwyzard]

hold

Sorry, I forgot about it, but I didn't mean to merge it just yet.
The idea was to use the build from the bot to test the impact, but then I got sidetracked.

[cmsbuild]

Pull request has been put on hold by @fwyzard
They need to issue an unhold command to remove the hold state or L1 can unhold it for all

[fwyzard]

It's only specific to this library because this is the only library for which we are currently using -Ofast.

[mandrenguyen]

Thanks I seem to recall some discussion about this flag in the context of reproducibility, perhaps in the context of GPU workflows.