$ git clone -n https://src.fedoraproject.org/rpms/rubygem-clutter.git /var/lib/mock/f41-build-740632-13309/root/chroot_tmpdir/scmroot/rubygem-clutter
Cloning into '/var/lib/mock/f41-build-740632-13309/root/chroot_tmpdir/scmroot/rubygem-clutter'...
$ git fetch origin ffa3087bb11e30e304559dcd47d11e06e8f7c386:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-clutter
 * [new ref]         ffa3087bb11e30e304559dcd47d11e06e8f7c386 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ffa3087 4.2.2 entry