$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugins-bad-free.git /var/lib/mock/f39-build-1503022-34955/root/chroot_tmpdir/scmroot/gstreamer1-plugins-bad-free
Cloning into '/var/lib/mock/f39-build-1503022-34955/root/chroot_tmpdir/scmroot/gstreamer1-plugins-bad-free'...
$ git fetch origin eaeb569b772b95bf7a0f9c02f9cc5f589fec4484:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugins-bad-free
 * [new ref]         eaeb569b772b95bf7a0f9c02f9cc5f589fec4484 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at eaeb569 Enable opencv as separate subpackage