Add debug statement

The debug option will show all defined targets with their dependencies
when uncommenting the line.

CMakeLists.txt

@@ -9,6 +9,9 @@
 cmake_minimum_required(VERSION 3.14.0 FATAL_ERROR)
 cmake_policy(VERSION 3.14...3.23)
 
+# uncomment the following line if you need to see all defined targets
+#set_property(GLOBAL PROPERTY GLOBAL_DEPENDS_DEBUG_MODE 1)
+
 # Define compiler on macosx to avoid problems when comparing to compilers
 # used for FairSoft/FairRoot compilation
 if(APPLE)