[13_1_X] Adding cov matrix to fakeBS object

[dzuolo]

PR description:

Following the changes in PR #41597 a fake beam spot object is now effectively used at HLT if none of the two fits produced by the DQM client converge.
This caused crashes at HLT (see #41914) because no cov matrix, and hence no errors, was assigned to the bs fake object.
This PR adds a cov matrix with non-zero diagonal elements close to the ones returned by the fit.

PR validation:

Minor changes: code compiles.

If this PR is a backport please specify the original PR and why you need to backport that PR. If this PR will be backported please specify to which release cycle the backport is meant for:

Backport of #42239

[cmsbuild]

A new Pull Request was created by @dzuolo (Davide Zuolo) for CMSSW_13_1_X.

It involves the following packages:

• RecoVertex/BeamSpotProducer (reconstruction, alca)

@perrotta, @consuegs, @clacaputo, @cmsbuild, @saumyaphor4252, @tvami, @mandrenguyen, @francescobrivio can you please review it and eventually sign? Thanks.
@VourMa, @GiacomoSguazzoni, @JanFSchulte, @tocheng, @VinInn, @missirol, @rovere, @mmusich, @mtosi, @dgulhan, @francescobrivio this is something you requested to watch as well.
@perrotta, @dpiparo, @rappoccio you are the release manager for this.

cms-bot commands are listed here

• Backported from [master] Adding cov matrix to fakeBS object #42239

[francescobrivio]

type bug-fix

[francescobrivio]

backport of #42239

[francescobrivio]

@cmsbuild please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-ac15cf/33657/summary.html
COMMIT: d1eadee
CMSSW: CMSSW_13_1_X_2023-07-11-2300/el8_amd64_gcc11
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/42240/33657/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 12 lines to the logs
• Reco comparison results: 191 differences found in the comparisons
• DQMHistoTests: Total files compared: 48
• DQMHistoTests: Total histograms compared: 3222791
• DQMHistoTests: Total failures: 5094
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3217675
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 47 files compared)
• Checked 207 log files, 159 edm output root files, 48 DQM output files
• TriggerResults: no differences found

[francescobrivio]

+1

• verbatim backport
• diffs in 12434.7 are known from spurious differences in outputs of Run-3 wfs *.7 #39803

[mandrenguyen]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_13_1_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_13_2_X is complete. This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @rappoccio (and backports should be raised in the release meeting by the corresponding L2)

[perrotta]

+1