ENH: superbuild: support custom compile chains

SuperBuild/CMakeLists.txt

@@ -48,7 +48,7 @@ else(UNIX)
   else()
     set(LDLIBVAR LD_LIBRARY_PATH)
     set(SB_ENV_CONFIGURE_CMD env ${LDLIBVAR}=${SB_INSTALL_PREFIX}/lib:$ENV{${LDLIBVAR}})
-    set(SB_CMAKE_COMMAND env ${LDLIBVAR}=${CMAKE_INSTALL_PREFIX}/lib  ${CMAKE_COMMAND})
+    set(SB_CMAKE_COMMAND env ${LDLIBVAR}=${CMAKE_INSTALL_PREFIX}/lib:$ENV{${LDLIBVAR}}  ${CMAKE_COMMAND})
     message(STATUS "Environment setup for Configure : ${SB_ENV_CONFIGURE_CMD}")
   endif()
 endif()