Hi, I am trying to use O=<dir> option when building kernel. It failed with missing .config file error. I checked out the message and found out it tried to read .config in the output directory. It's strange because there is no command to copy .config to the output directory. I tested v4.14 and v4.15, and both failed. I googled that error message and found one thread in the stackoverflow: https://stackoverflow.com/questions/28603372/kernel-compilation-not-finding-... Is it two years old but not fixed yet? Or did I use O= option wrong? FYI, following is my error message. gohkim@ws00837:~/work/linux-torvalds$ make O=./output V=1 make -C /home/gohkim/work/linux-torvalds/output KBUILD_SRC=/home/gohkim/work/linux-torvalds \ -f /home/gohkim/work/linux-torvalds/Makefile make[1]: Entering directory '/home/gohkim/work/linux-torvalds/output' make -f ../scripts/Makefile.build obj=arch/x86/entry/syscalls all make -f ../scripts/Makefile.build obj=scripts/basic (cat /dev/null; ) > scripts/basic/modules.order rm -f .tmp_quiet_recordmcount make -f ../scripts/Makefile.build obj=arch/x86/tools relocs make -f ../Makefile silentoldconfig make -f ../scripts/Makefile.build obj=scripts/basic (cat /dev/null; ) > scripts/basic/modules.order rm -f .tmp_quiet_recordmcount ln -fsn .. source /bin/bash ../scripts/mkmakefile \ .. . 4 15 GEN ./Makefile make -f ../scripts/Makefile.build obj=scripts/kconfig silentoldconfig mkdir -p include/config include/generated test -e include/generated/autoksyms.h || \ touch include/generated/autoksyms.h scripts/kconfig/conf --silentoldconfig Kconfig *** *** Configuration file ".config" not found! *** *** Please run some configurator (e.g. "make oldconfig" or *** "make menuconfig" or "make xconfig"). *** ../scripts/kconfig/Makefile:38: recipe for target 'silentoldconfig' failed make[3]: *** [silentoldconfig] Error 1 ../Makefile:524: recipe for target 'silentoldconfig' failed make[2]: *** [silentoldconfig] Error 2 /home/gohkim/work/linux-torvalds/Makefile:604: recipe for target 'include/config/auto.conf' failed make[1]: *** [include/config/auto.conf] Error 2 make[1]: Leaving directory '/home/gohkim/work/linux-torvalds/output' Makefile:146: recipe for target 'sub-make' failed make: *** [sub-make] Error 2 -- Best regards, Gioh Kim