Hi Frank, First bad commit (maybe != root cause): tree: https://github.com/frank-w/BPI-R2-4.14 5.11-mt76test head: 5d6e12bac94e425c29b890e7aa9e027a2edf9142 commit: 5d6e12bac94e425c29b890e7aa9e027a2edf9142 [19/19] mt76: add openwrt-version with additional patches config: x86_64-randconfig-a003-20210215 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://github.com/frank-w/BPI-R2-4.14/commit/5d6e12bac94e425c29b890e7aa9... git remote add frank-w-bpi-r2-4.14 https://github.com/frank-w/BPI-R2-4.14 git fetch --no-tags frank-w-bpi-r2-4.14 5.11-mt76test git checkout 5d6e12bac94e425c29b890e7aa9e027a2edf9142 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): make[6]: Failed to remake makefile 'drivers/net/wireless/mediatek/mt76_test/Makefile'. make[5]: *** [scripts/Makefile.clean:71: drivers/net/wireless/mediatek/mt76_test] Error 2 make[5]: Target '__clean' not remade because of errors. make[4]: *** [scripts/Makefile.clean:71: drivers/net/wireless/mediatek] Error 2 make[4]: Target '__clean' not remade because of errors. make[3]: *** [scripts/Makefile.clean:71: drivers/net/wireless] Error 2 make[3]: Target '__clean' not remade because of errors. make[2]: *** [scripts/Makefile.clean:71: drivers/net] Error 2 make[2]: Target '__clean' not remade because of errors. make[1]: *** [Makefile:1812: _clean_drivers] Error 2 make[1]: Target 'distclean' not remade because of errors. make: *** [Makefile:185: __sub-make] Error 2 make: Target 'distclean' not remade because of errors. vim +15 scripts/Makefile.clean 2315c6e4227815 Sam Ravnborg 2005-07-25 12 2a691470345a00 Sam Ravnborg 2005-07-25 13 # The filename Kbuild has precedence over Makefile db8c1a7b2ca25f Sam Ravnborg 2005-07-27 14 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) db8c1a7b2ca25f Sam Ravnborg 2005-07-27 @15 include $(if $(wildcard $(kbuild-dir)/Kbuild), $(kbuild-dir)/Kbuild, $(kbuild-dir)/Makefile) ^1da177e4c3f41 Linus Torvalds 2005-04-16 16 :::::: The code at line 15 was first introduced by commit :::::: db8c1a7b2ca25f37b1429c00e82d6568f86caec1 kbuild: fix building external modules :::::: TO: Sam Ravnborg <sam(a)mars.(none)&gt; :::::: CC: Sam Ravnborg <sam(a)mars.(none)&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org