Updated CMake build to better control RPATH values when building

CMakeLists.txt

@@ -77,16 +77,20 @@ FILE(TO_CMAKE_PATH ${PY} PY)
 
 INCLUDE(GNUInstallDirs)
 IF (SKBUILD)
+    SET(INSTALL_INCLUDEDIR ${SKBUILD_HEADERS_DIR}) 
     SET(INSTALL_PYPROJ ${SKBUILD_PLATLIB_DIR}/${SKBUILD_PROJECT_NAME}) 
     SET(INSTALL_BINDIR ${INSTALL_PYPROJ})
     IF (CIBUILDWHEEL)
         SET(INSTALL_LIBDIR ${CMAKE_BINARY_DIR}/lib)
         SET(CMAKE_INSTALL_RPATH "${CMAKE_BINARY_DIR}/bin")
     ELSE()
         SET(INSTALL_LIBDIR ${INSTALL_BINDIR})
-        SET(CMAKE_INSTALL_RPATH "${INSTALL_LIBDIR}")
+        IF (APPLE)
+            SET(CMAKE_INSTALL_RPATH "@loader_path;${INSTALL_LIBDIR}")
+        ELSEIF (LINUX)
+            SET(CMAKE_INSTALL_RPATH "@ORIGIN;${INSTALL_LIBDIR}")
+        ENDIF ()
     ENDIF()
-    SET(INSTALL_INCLUDEDIR ${SKBUILD_HEADERS_DIR}) 
 ELSE ()
     SET(INSTALL_PYPROJ ${PY})
     SET(INSTALL_BINDIR ${CMAKE_INSTALL_BINDIR})
@@ -124,6 +128,8 @@ ENDIF()
 # Set the name of the ctem library
 SET(CTEM_LIBRARY ${SKBUILD_PROJECT_NAME})
 
+SET(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
 # The source for the CTEM binary and have it placed in the bin folder
 ADD_SUBDIRECTORY(${SRC} ${BIN})