Draft: DerivationFrameworkConfiguration+Higgs+JetETMiss+LLP: Another overlap-removal sequencing fix.

To work around the fact that overlap removal overwrites decorations, we need to group all the overlap removal algorithms after all other derivation algorithms, followed by the algorithms to lock the decorations.

We were doing this by moving the sequences to the end in the individual format configurations. But this can fail if multiple formats are combined.

Instead, in the skeleton, we introduce a sequence DerivationEndSeq that will be put after all other derivation algorithms. Then we can add the cleaning algorithms to this.

See ATLASRECTS-8008.

PhysicsAnalysis/DerivationFramework/DerivationFrameworkConfiguration/python/DerivationSkeleton.py

-# Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
+# Copyright (C) 2002-2025 CERN for the benefit of the ATLAS collaboration
 
 import sys
 
@@ -112,10 +112,21 @@ def fromRunArgs(runArgs):
        from AthenaServices.MetaDataSvcConfig import MetaDataSvcCfg
        cfg.merge(MetaDataSvcCfg(flags, ['IOVDbMetaDataTool']))
 
+    # Make a sequence that will run after all other derivation
+    # algorithms.
+    cfg.addSequence(CompFactory.AthSequencer('DerivationEndSeq', Sequential=True),
+                    parentName = 'AthAlgSeq')
+
+    # Process all derivation formats.
     for formatName in formats:
         derivationConfig = getattr(DerivationConfigList, f'{formatName}Cfg')
         cfg.merge(derivationConfig(flags))
 
+    # Now move the end sequence to the end.
+    seq = cfg.getSequence('AthAlgSeq')
+    derivationEndSeq = cfg.getSequence('DerivationEndSeq')
+    seq.Members = [a for a in seq.Members if a is not derivationEndSeq] + [derivationEndSeq]
+
     # Pass-through mode (ignore skimming and accept all events)
     if hasattr(runArgs, 'passThrough'):
         logDerivation.info('Pass-through mode was requested. All events will be written to the output.')