eg.
target_include_directories( ${CANONICAL_LIB_NAME} PRIVATE
"../../include"
${bitcoin_system_INCLUDE_DIRS} )
here ${bitcoin_system_INCLUDE_DIRS} is empty for me and that results in cmake finding the wrong library (the system installed version, not the one I want to use, i.e. version 4). Meaning I get compile errors because there is now a version mismatch