reproduce (this is a W=1 build):
        # https://github.com/intel/linux-intel-lts/commit/0a2bddb4a08e2bc9f2ba04a7b7acd99668d52a37
        git remote add intel-lts https://github.com/intel/linux-intel-lts.git
        git fetch --no-tags intel-lts 6.6/dovetail-xenomai
        git checkout 0a2bddb4a08e2bc9f2ba04a7b7acd99668d52a37
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/xen/