[BuildRules] Allow to use different python to compile package/python

[smuzaffar]

In order to suppot python3 only cmssw packages , now build rules allows to add the following in package/python/BuildFile.xml to compile/test this package with python3 . Default is to test with python

<flags PYTHON_VERSION="3"/>

[cmsbuild]

A new Pull Request was created by @smuzaffar (Malik Shahzad Muzaffar) for branch IB/CMSSW_11_2_X/master.

@cmsbuild, @smuzaffar, @mrodozov can you please review it and eventually sign? Thanks.
cms-bot commands are listed here

[smuzaffar]

test parameters:

• full_cmssw = true

[smuzaffar]

please test

[cmsbuild]

The tests are being triggered in jenkins.
Test Parameters:

• BUILD_FULL_CMSSW = true
• CMSSW_11_2_X_2020-09-17-1100/slc7_amd64_gcc820: https://cmssdt.cern.ch/jenkins/job/ib-run-pr-tests/9403/console Started: 2020/09/17 15:15

[cmsbuild]

+1
Tested at: 5e1cf44
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-b02e67/9403/summary.html
CMSSW: CMSSW_11_2_X_2020-09-17-1100
SCRAM_ARCH: slc7_amd64_gcc820

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-b02e67/9403/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 35
• DQMHistoTests: Total histograms compared: 2540471
• DQMHistoTests: Total failures: 7
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2540442
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 34 files compared)
• Checked 149 log files, 22 edm output root files, 35 DQM output files

[smuzaffar]

+externals

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IB/CMSSW_11_2_X/master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @silviodonato, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)