Hi, I'm unable to build the kernel using the O=path/to/out option. Am I doing something brain dead? $ cd $KERNEL $ make mrproper $ cp path/to/valid/config/file .config $ make O=/abs/path/to/output ... scripts/kconfig/conf --syncconfig Kconfig *** *** Configuration file ".config" not found! *** *** Please run some configurator (e.g. "make oldconfig" or *** "make menuconfig" or "make xconfig"). ... So I tried copying the .config file to the output directory $ cp .config /abs/path/to/output $ make O=/abs/path/to/output ... Using /home/tobin/build/kernel/linux as source for kernel /home/tobin/build/kernel/linux is not clean, please run 'make mrproper' in the '/home/tobin/build/kernel/linux' directory. /home/tobin/build/kernel/linux/Makefile:1091: recipe for target 'prepare3' failed make[1]: *** [prepare3] Error 1 make[1]: Leaving directory '/home/tobin/build/kernel/output/master' Makefile:146: recipe for target 'sub-make' failed make: *** [sub-make] Error 2 Same thing if I use KBUILD_OUTPUT instead of passing O= thanks, Tobin.