[Sherpa] Update Sherpa to 2.2.16 and compile with HepMC3

[shimashimarin]

• Update Sherpa to v2.2.16, which include a bugfix of Enhance_Factor.
• Include HepMC3 when building Sherpa. To be ready for the GenTask#53.
• Clean/update some patch files.

Recola1 integration as in PR #10200 could be postponed and discussed further.

[cmsbuild]

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

@akritkbehera, @cmsbuild, @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

[smuzaffar]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-12eee4/51740/summary.html
COMMIT: 5f6a52c
CMSSW: CMSSW_16_1_X_2026-03-03-2300/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmsdist/10392/51740/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 17 lines to the logs
• Reco comparison results: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4180442
• DQMHistoTests: Total failures: 64
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4180358
• 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

[smuzaffar]

please test for el9_amd64_gcc15

[smuzaffar]

assign generators

@cms-sw/generators-l2 , can you please review and sign this update?

[cmsbuild]

New categories assigned: generators

@lviliani,@mkirsano,@sensrcn,@theofil you have been requested to review this Pull request/Issue and eventually sign? Thanks

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-12eee4/51749/summary.html
COMMIT: 5f6a52c
CMSSW: CMSSW_16_1_X_2026-03-03-2300/el9_amd64_gcc15
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmsdist/10392/51749/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 47 lines to the logs
• ROOTFileChecks: Some differences in event products or their sizes found
• Reco comparison results: 101656 differences found in the comparisons
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4180442
• DQMHistoTests: Total failures: 533527
• DQMHistoTests: Total nulls: 317
• DQMHistoTests: Total successes: 3646578
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.18700000000000028 KiB( 52 files compared)
• DQMHistoSizes: changed ( 10224.0 ): -0.352 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 13034.0 ): -0.176 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 17034.0 ): 2.501 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 18634.0 ): 4.630 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 2023.0020001,... ): -0.012 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0000001,... ): -0.004 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0020001,... ): 0.004 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0040001 ): -0.039 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 2024.0050001,... ): 0.008 KiB JetMET/SUSYDQM
• DQMHistoSizes: changed ( 250202.181 ): 0.293 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 25202.0 ): ...
• Checked 227 log files, 198 edm output root files, 53 DQM output files

[theofil]

+1

[smuzaffar]

+externals

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IB/CMSSW_16_1_X/master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @sextonkennedy, @mandrenguyen, @ftenchini (and backports should be raised in the release meeting by the corresponding L2)