Add more context to exception message in externalGenerator

[Dr15Jones]

PR description:

• Add what the program was doing when the exception happened.
• Make it easier to spot exception message in the log

PR validation:

Code compiles and unit tests show the new information.

[Dr15Jones]

NOTE: in the IBs we are getting infrequent failures of the externalGenerator where BOOST is throwing an exception with a not-so-informative message (i.e. just a generic library error). I'm hoping having our side print more info might help track down what is actually happening.

[Dr15Jones]

please test

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-37871/29835

• This PR adds an extra 12KB to repository

[cmsbuild]

A new Pull Request was created by @Dr15Jones (Chris Jones) for master.

It involves the following packages:

• GeneratorInterface/Core (generators)

@alberto-sanchez, @SiewYan, @mkirsano, @Saptaparna, @GurpreetSinghChahal can you please review it and eventually sign? Thanks.
@alberto-sanchez, @mkirsano 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

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-5ed0e8/24545/summary.html
COMMIT: 3963910
CMSSW: CMSSW_12_4_X_2022-05-09-1100/slc7_amd64_gcc10
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/37871/24545/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 6 differences found in the comparisons
• DQMHistoTests: Total files compared: 49
• DQMHistoTests: Total histograms compared: 3696633
• DQMHistoTests: Total failures: 14
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3696597
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 48 files compared)
• Checked 206 log files, 45 edm output root files, 49 DQM output files
• TriggerResults: no differences found

[SiewYan]

Unit test does show new information[*].

[*] https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-5ed0e8/24545/unitTests/src/GeneratorInterface/Core/test/FailingGeneratorFilterTest/testing.log

[SiewYan]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). 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)

[qliphy]

+1