$ git clone -n https://src.fedoraproject.org/rpms/gutenprint.git /var/lib/mock/f40-build-2048612-48993/root/chroot_tmpdir/scmroot/gutenprint
Cloning into '/var/lib/mock/f40-build-2048612-48993/root/chroot_tmpdir/scmroot/gutenprint'...
$ git fetch origin 39bf539164831918085055c8291352a6feb78a10:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gutenprint
 * [new ref]         39bf539164831918085055c8291352a6feb78a10 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 39bf539 Mention when the macro definition can be removed