reproduce (this is a W=1 build):
        git remote add sailus-media-tree git://linuxtv.org/sailus/media_tree.git
        git fetch --no-tags sailus-media-tree metadata
        git checkout dbb6c78ee163822abba87ee352b67b7cfec3a023
        # 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 drivers/media/v4l2-core/