$ git clone -n https://src.fedoraproject.org/rpms/media-downloader.git /var/lib/mock/f40-build-2703077-70760/root/chroot_tmpdir/scmroot/media-downloader
Cloning into '/var/lib/mock/f40-build-2703077-70760/root/chroot_tmpdir/scmroot/media-downloader'...
$ git fetch origin 63970af9daa2fd7703d50839a2e0bfc497ec60e6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/media-downloader
 * [new ref]         63970af9daa2fd7703d50839a2e0bfc497ec60e6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 63970af Update to 4.5.0