reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8164dd6c8ae158ec0740bf37f0f14645a1fb5355
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 8164dd6c8ae158ec0740bf37f0f14645a1fb5355
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/block/drbd/