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/20260819054525.2325031-1-lijun01@kylinos.cn

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=nios2 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=nios2 SHELL=/bin/bash drivers/bluetooth/ drivers/usb/gadget/function/