$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugins-good.git /var/lib/mock/f39-build-2310240-57404/root/chroot_tmpdir/scmroot/gstreamer1-plugins-good
Cloning into '/var/lib/mock/f39-build-2310240-57404/root/chroot_tmpdir/scmroot/gstreamer1-plugins-good'...
$ git fetch origin 45fdd9b88627d2b9d5f4b240fce42e6e56816f03:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugins-good
 * [new ref]         45fdd9b88627d2b9d5f4b240fce42e6e56816f03 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 45fdd9b Merge branch 'rawhide' into f39