$ git clone -n https://src.fedoraproject.org/rpms/xine-lib.git /var/lib/mock/f40-build-789132-135592/root/chroot_tmpdir/scmroot/xine-lib
Cloning into '/var/lib/mock/f40-build-789132-135592/root/chroot_tmpdir/scmroot/xine-lib'...
$ git fetch origin ac9527abbc570c79ac4cec2e6396fed9a9070c45:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xine-lib
 * [new ref]         ac9527abbc570c79ac4cec2e6396fed9a9070c45 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ac9527a Rebuild for libvpx 1.14.x