[Core][RH8] Fix unit test to use python3

[smuzaffar]

This should fix the unit test for RHEL8 IBs where we do not have python (python2) installed

[smuzaffar]

please test

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-37293/28929

• This PR adds an extra 12KB to repository

[cmsbuild]

A new Pull Request was created by @smuzaffar (Malik Shahzad Muzaffar) for master.

It involves the following packages:

• IOPool/Common (core)

@makortel, @smuzaffar, @Dr15Jones can you please review it and eventually sign? Thanks.
@makortel, @wddgit this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[smuzaffar]

+core
unit test passed

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs after it passes the integration tests. This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[cmsbuild]

-1

Failed Tests: RelVals-INPUT
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-61c884/23260/summary.html
COMMIT: 117ed3c
CMSSW: CMSSW_12_4_X_2022-03-21-1100/slc7_amd64_gcc10
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/37293/23260/install.sh to create a dev area with all the needed externals and cmssw changes.

RelVals-INPUT

The relvals timed out after 4 hours.

Comparison Summary

@slava77 comparisons for the following workflows were not done due to missing matrix map:

• /data/cmsbld/jenkins/workspace/compare-root-files-short-matrix/data/PR-61c884/39434.911_TTbar_14TeV+2026D88_DD4hep+TTbar_14TeV_TuneCP5_GenSimHLBeamSpot14+DigiTrigger+RecoGlobal+HARVESTGlobal

Summary:

• No significant changes to the logs found
• Reco comparison results: 2 differences found in the comparisons
• DQMHistoTests: Total files compared: 49
• DQMHistoTests: Total histograms compared: 3695650
• DQMHistoTests: Total failures: 51221
• DQMHistoTests: Total nulls: 66
• DQMHistoTests: Total successes: 3644341
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.004 KiB( 48 files compared)
• DQMHistoSizes: changed ( 312.0 ): 0.004 KiB MessageLogger/Warnings
• Checked 204 log files, 45 edm output root files, 49 DQM output files
• TriggerResults: no differences found

[perrotta]

+1

[perrotta]

merge
(unit test succeeds)