Merge branch 'AthSimulationCMakeFix-main-20240228' into 'main'

AthSimulation CMake Fixes, main branch (2024.02.28.)

See merge request atlas/athena!69337

Projects/AthSimulation/CMakeLists.txt

-# Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+# Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 
 # Set up the project.
 cmake_minimum_required( VERSION 3.6 )
@@ -22,6 +22,7 @@ set( ATLAS_PYTHON_CHECKER ${ATLAS_FLAKE8}
 find_package( AtlasCMake QUIET )
 
 # Find the base project(s):
+set( LCG_COMPONENTS "externals" CACHE STRING "LCG components to set up" )
 find_package( AthSimulationExternals REQUIRED )
 find_package( Gaudi )
 

Projects/AthSimulation/cmake/PreConfig.cmake.in

-# Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+# Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 #
 # Pre-config script to propagate variables to downstream projects
 #
@@ -29,6 +29,13 @@ if( @CMAKE_PROJECT_NAME@_FIND_QUIETLY )
   set( _quietFlag QUIET )
 endif()
 
+# Set up the correct version of LCG. While AthSimulationExternals does this as
+# well, we need to do it explicitly here, to make the following find_package
+# calls find the packages correctly.
+set( LCG_VERSION_POSTFIX @LCG_VERSION_POSTFIX@ )
+set( LCG_COMPONENTS "@LCG_COMPONENTS@" CACHE STRING "LCG components to set up" )
+find_package( LCG @LCG_VERSION_NUMBER@ REQUIRED EXACT ${_quietFlag} )
+
 # Imported target(s) used by the project.
 find_package( nlohmann_json ${_quietFlag} )
 find_package( GTest ${_quietFlag} )