reproduce (this is a W=1 build):
        git remote add bluetooth https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git
        git fetch bluetooth master
        git checkout bluetooth/master
        b4 shazam https://lore.kernel.org/r/20260417104639.2608008-1-tristmd@gmail.com

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=um olddefconfig
        make W=1 O=build_dir ARCH=um SHELL=/bin/bash