LVGL Release v8.0编译报错（20211214-01）：error: unused variable 'obj'

static void event_handler(lv_event_t * e)
{
    lv_obj_t * obj = lv_event_get_target(e);
    LV_LOG_USER("Button %d clicked", lv_obj_get_child_id(obj));
}

编译报错如下LOG：

Compiling lv_example_win_1.c
cc1: warnings being treated as errors
PluginSM/lvgl_release_v8.0/./lvgl/examples/widgets/win/lv_example_win_1.c: In function 'event_handler':
PluginSM/lvgl_release_v8.0/./lvgl/examples/widgets/win/lv_example_win_1.c:7: error: unused variable 'obj'
../../../../MakeCommon/MakeCommon.txt:625: recipe for target 'lvgl_release_v8.0_Data/Release/ObjectCode/lv_example_win_1.o' failed
make[1]: *** [lvgl_release_v8.0_Data/Release/ObjectCode/lv_example_win_1.o] Error 1
../../../../MakeCommon/OutputLib.txt:154: recipe for target 'release' failed
make: *** [release] Error 2

一种处理方式，可以解决编译报错

static void event_handler(lv_event_t * e)
{
    lv_obj_t * obj ;
    obj = lv_event_get_target(e);
    LV_LOG_USER("Button %d clicked", lv_obj_get_child_id(obj));
}