$ git clone -n https://src.fedoraproject.org/rpms/rubygem-clutter-gstreamer.git /var/lib/mock/f39-build-1582863-38121/root/chroot_tmpdir/scmroot/rubygem-clutter-gstreamer
Cloning into '/var/lib/mock/f39-build-1582863-38121/root/chroot_tmpdir/scmroot/rubygem-clutter-gstreamer'...
$ git fetch origin 5fe34c92a16d4f2da73d3563b068c98a5ff0fcd3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-clutter-gstreamer
 * [new ref]         5fe34c92a16d4f2da73d3563b068c98a5ff0fcd3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5fe34c9 4.2.0 entry