acts: fix for building with newer eigen and avoid picking up system python

[smuzaffar]

FYI @fwyzard

This should fix the PY312 build errors (added missing cassert include : cms-externals/acts#1 ) and make sure cmake picks up python3 from CMS externals ( fixes issues seen in here

[smuzaffar]

please test

[cmsbuild]

A new Pull Request was created by @smuzaffar for branch IB/CMSSW_16_0_X/master.

@akritkbehera, @iarspider, @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 for CMSSW_16_0_PY312_X

[smuzaffar]

+externals

Py312 externals build successfully.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IB/CMSSW_16_0_X/master 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

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-102db2/49223/summary.html
COMMIT: b1e6fb8
CMSSW: CMSSW_16_0_X_2025-11-03-2300/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10170/49223/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:

• @fwyzard Pass CMake GPU flags only when GPU support is enabled #10166

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-102db2/49223/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-102db2/49223/git-merge-result

Comparison Summary

Summary:

• You potentially removed 3 lines from the logs
• Reco comparison results: 7 differences found in the comparisons
• DQMHistoTests: Total files compared: 51
• DQMHistoTests: Total histograms compared: 3939953
• DQMHistoTests: Total failures: 43
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3939890
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 50 files compared)
• Checked 218 log files, 188 edm output root files, 51 DQM output files
• TriggerResults: no differences found

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-102db2/49224/summary.html
COMMIT: b1e6fb8
CMSSW: CMSSW_16_0_PY312_X_2025-11-03-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10170/49224/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:

• @fwyzard Pass CMake GPU flags only when GPU support is enabled #10166
• @fwyzard Integrate Acts v44.0.1 (with minimal changes) as an external #10156
• @cms-sw Update tag for DQM-Integration to V00-12-00 #10168

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-102db2/49224/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-102db2/49224/git-merge-result

Comparison Summary

Summary:

• You potentially added 197 lines to the logs
• Reco comparison results: 877 differences found in the comparisons
• DQMHistoTests: Total files compared: 51
• DQMHistoTests: Total histograms compared: 3939953
• DQMHistoTests: Total failures: 3688
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3936245
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 50 files compared)
• Checked 218 log files, 188 edm output root files, 51 DQM output files
• TriggerResults: no differences found