Spurious log differences reported

[kpedro88]

I have noticed in #48009 that the PR comparison says:

You potentially added 180 lines to the logs

The changes are claimed to look like this:

0 Lines only in /data/cmsbld/jenkins/workspace/compare-root-files-short-matrix/data/CMSSW_15_1_X_2025-05-07-2300/1000.0_RunMinBias2011A/step3_RunMinBias2011A.log
1 Lines only in /data/cmsbld/jenkins/workspace/compare-root-files-short-matrix/data/PR-d736d9/1000.0_RunMinBias2011A/step3_RunMinBias2011A.log
Starting cmsRun -j JobReport3.xml step3_SKIM.py
You added 1 to /data/cmsbld/jenkins/workspace/compare-root-files-short-matrix/data/PR-d736d9/1000.0_RunMinBias2011A/step5_RunMinBias2011A.log

However, if I actually look at these logs, I see the following:

Baseline:

Starting env LD_PRELOAD=libPerfToolsAllocMonitorPreload.so:libPerfToolsMaxMemoryPreload.so cmsRun -j JobReport3.xml step3_SKIM.py

PR:

Starting cmsRun -j JobReport3.xml step3_SKIM.py

I am not sure a) why they are different or b) why the diff does not pick up that it is a difference but instead thinks that it is an added line. It would be useful to fix this so it is not reporting spurious additions, which can confuse the PR review.

[cmsbuild]

cms-bot internal usage

[cmsbuild]

A new Issue was created by @kpedro88.

@Dr15Jones, @antoniovilela, @makortel, @mandrenguyen, @rappoccio, @sextonkennedy, @smuzaffar can you please review it and eventually sign/assign? Thanks.

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[makortel]

assign core

[cmsbuild]

New categories assigned: core

@Dr15Jones,@makortel,@smuzaffar you have been requested to review this Pull request/Issue and eventually sign? Thanks

[makortel]

a) why they are different

I'd bet the "why" is being investigated in #2494 / cms-sw/cmssw#48030