reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/hare/scsi-devel.git/commit/?id=89bc5b1f20c3cea7aa079e9e5c30e8aa86b5621b
        git remote add hare-scsi-devel https://git.kernel.org/pub/scm/linux/kernel/git/hare/scsi-devel.git
        git fetch --no-tags hare-scsi-devel configfs-ns.v3
        git checkout 89bc5b1f20c3cea7aa079e9e5c30e8aa86b5621b

        # 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