openwrt编译出错 求助！

elliot

/root/openwrt/build_dir/target-mipsel_24kc_glibc/fstools-2018-01-02-11efbf3b/libfstools/overlay.c:249:3: warning: ignoring return value of 'system', declared with attribute warn_unused_result [-Wunused-result]
   system("cp -a /tmp/root/upper/* / 2>/dev/null");
   ^
/root/openwrt/build_dir/target-mipsel_24kc_glibc/fstools-2018-01-02-11efbf3b/libfstools/overlay.c: At top level:
cc1: error: unrecognized command line option '-Wno-format-truncation' [-Werror]
cc1: all warnings being treated as errors
CMakeFiles/fstools.dir/build.make:110: recipe for target 'CMakeFiles/fstools.dir/libfstools/overlay.c.o' failed
make[6]: *** [CMakeFiles/fstools.dir/libfstools/overlay.c.o] Error 1
make[6]: Leaving directory '/root/openwrt/build_dir/target-mipsel_24kc_glibc/fstools-2018-01-02-11efbf3b'
CMakeFiles/Makefile2:252: recipe for target 'CMakeFiles/fstools.dir/all' failed
make[5]: *** [CMakeFiles/fstools.dir/all] Error 2
make[5]: Leaving directory '/root/openwrt/build_dir/target-mipsel_24kc_glibc/fstools-2018-01-02-11efbf3b'
Makefile:129: recipe for target 'all' failed
make[4]: *** [all] Error 2
make[4]: Leaving directory '/root/openwrt/build_dir/target-mipsel_24kc_glibc/fstools-2018-01-02-11efbf3b'
Makefile:118: recipe for target '/root/openwrt/build_dir/target-mipsel_24kc_glibc/fstools-2018-01-02-11efbf3b/.built' failed
make[3]: *** [/root/openwrt/build_dir/target-mipsel_24kc_glibc/fstools-2018-01-02-11efbf3b/.built] Error 2
make[3]: Leaving directory '/root/openwrt/package/system/fstools'
package/Makefile:109: recipe for target 'package/system/fstools/compile' failed
make[2]: *** [package/system/fstools/compile] Error 2
make[2]: Leaving directory '/root/openwrt'
package/Makefile:105: recipe for target '/root/openwrt/staging_dir/target-mipsel_24kc_glibc/stamp/.package_compile' failed
make[1]: *** [/root/openwrt/staging_dir/target-mipsel_24kc_glibc/stamp/.package_compile] Error 2
make[1]: Leaving directory '/root/openwrt'
/root/openwrt/include/toplevel.mk:216: recipe for target 'world' failed
make: *** [world] Error 2