reproduce (this is a W=1 build):
        git remote add kdave https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git
        git fetch kdave for-next
        git checkout kdave/for-next
        b4 shazam https://lore.kernel.org/r/e163012ed80a4f55ce17641586681c6ac4ff9018.1724859620.git.dsterba@suse.com
        # 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 fs/btrfs/