Patch herwig to use python3 when running madgraph in the Matchbox

[Dominic-Stafford]

Fix for cms-sw/cmssw#34529 - patch herwig matchbox to call madgraph with python3 rather than python2. Tested this fixes workflow 511 (Herwig matchbox)

[cmsbuild]

A new Pull Request was created by @Dominic-Stafford for branch IB/CMSSW_12_0_X/master.

@cmsbuild, @smuzaffar, @mrodozov, @iarspider can you please review it and eventually sign? Thanks.
@silviodonato, @dpiparo, @qliphy, @perrotta you are the release manager for this.
cms-bot commands are listed here

[qliphy]

please test workflow 511.0

[cmsbuild]

-1

Failed Tests: UnitTests RelVals
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-142ca2/17092/summary.html
COMMIT: 59fe866
CMSSW: CMSSW_12_0_X_2021-07-21-2300/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/7158/17092/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 scram-tools repo to provide scram toolfile definitions #7147
• @cms-sw Download tensorboard data server soruces from githhub to fix cc8 builds #7153

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-142ca2/17092/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-142ca2/17092/git-merge-result

Unit Tests

I found errors in the following unit tests:

---> test test_MuonGeometryDBConverter had ERRORS
---> test testDD4hepCompactView had ERRORS
---> test testDD4hepFilteredView had ERRORS
---> test testDD4hepFilteredViewFind had ERRORS
and more ...

RelVals

• 11634.911

----- Begin Fatal Exception 22-Jul-2021 20:16:08 CEST-----------------------
An exception of category 'StdException' occurred while
   [0] Running EventSetup component DDDetectorESProducer/'
Exception Message:
A std::exception was thrown.
An exception of category 'FileInPathError' occurred.
Exception Message:
edm::FileInPath unable to find file Geometry/VeryForwardData/data/RP_Vertical_Device/2021/v1/RP_Vertical_Device.xml anywhere in the search path.
The search path is defined by: CMSSW_SEARCH_PATH
${CMSSW_SEARCH_PATH} is: /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/7158/17092/CMSSW_12_0_X_2021-07-21-2300/poison:/cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/7158/17092/CMSSW_12_0_X_2021-07-21-2300/src:/cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/7158/17092/CMSSW_12_0_X_2021-07-21-2300/external/slc7_amd64_gcc900/data:/cvmfs/cms-ib.cern.ch/week0/slc7_amd64_gcc900/cms/cmssw/CMSSW_12_0_X_2021-07-21-2300/src
Current directory is: /data/cmsbld/jenkins/workspace/ib-run-pr-relvals/runTheMatrix-results/11634.911_TTbar_14TeV+2021_DD4hep+TTbar_14TeV_TuneCP5_GenSim+Digi+Reco+HARVEST+ALCA

dd4hep: Error interpreting XML nodes of type <Include/>
dd4hep: Error interpreting XML nodes of type <IncludeSection/>
dd4hep: while parsing /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/7158/17092/CMSSW_12_0_X_2021-07-21-2300/src/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2021.xml
dd4hep: with plugin:DD4hep_CompactLoader
----- End Fatal Exception -------------------------------------------------

[smuzaffar]

+externals
looks good, workflow 511.0 ran fine

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IB/CMSSW_12_0_X/master IBs (but tests are reportedly failing). This pull request will now be reviewed by the release team before it's merged. @silviodonato, @dpiparo, @qliphy, @perrotta (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

@Dominic-Stafford

It seems the error with workflow 511 is still there in recent IB:

https://cmssdt.cern.ch/SDT/cgi-bin/logreader/slc7_amd64_gcc900/CMSSW_12_0_X_2021-07-24-1100/pyRelValMatrixLogs/run/511.0_QCD_Pt-30_13TeV_aMCatNLO_herwig7+QCD_Pt-30_13TeV_aMCatNLO_herwig7+HARVESTGEN/step1_QCD_Pt-30_13TeV_aMCatNLO_herwig7+QCD_Pt-30_13TeV_aMCatNLO_herwig7+HARVESTGEN.log#/

Can you have a check?

After this PR gets merged in CMSSW_12_0_X_2021-07-23-1100
this error did disappear. However, it came back afterwards in next IBs.

[smuzaffar]

@qliphy , as 511.0 is working in PY3 IBs ( where python is python3) so hopefull #7167 should fix this issue where I have replaced few more python to python3.