"fix copy go master lib2python"

python/CMakeLists.txt

@@ -13,8 +13,11 @@ set(PY_FILES paddle/__init__.py
   ${V2_PY_FILES})
 
 add_custom_target(copy_paddle_master)
+
+SET(COPY_PADDLE_MASTER "")
 if(WITH_GOLANG)
-  add_custom_command(TARGET copy_paddle_master
+  SET(COPY_PADDLE_MASTER "copy_paddle_master")
+  add_custom_command(TARGET ${COPY_PADDLE_MASTER}
     COMMAND cp ${paddle_master_LIB_PATH} ${PROJ_ROOT}/python/paddle/v2/master/
     )
   add_dependencies(copy_paddle_master paddle_master)
@@ -26,7 +29,7 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/setup.py.in
 add_custom_command(OUTPUT ${OUTPUT_DIR}/.timestamp
     COMMAND env ${py_env} ${PYTHON_EXECUTABLE} setup.py bdist_wheel
     COMMAND ${CMAKE_COMMAND} -E touch ${OUTPUT_DIR}/.timestamp
-    DEPENDS gen_proto_py ${PY_FILES} ${external_project_dependencies} copy_paddle_master)
+    DEPENDS gen_proto_py ${PY_FILES} ${external_project_dependencies} ${COPY_PADDLE_MASTER})
 
 add_custom_target(paddle_python ALL DEPENDS
     ${OUTPUT_DIR}/.timestamp)