reproduce (this is a W=1 build):
        git remote add linux-nvme git://git.infradead.org/nvme.git
        git fetch --no-tags linux-nvme nvme-6.11
        git checkout ff5ff45d19d8b13ceef35948204b08a51000f15f
        # 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 drivers/nvme/host/