$ git clone -n https://src.fedoraproject.org/rpms/rubygem-sugarjar.git /var/lib/mock/f45-build-35334-694/root/chroot_tmpdir/scmroot/rubygem-sugarjar
Cloning into '/var/lib/mock/f45-build-35334-694/root/chroot_tmpdir/scmroot/rubygem-sugarjar'...
$ git fetch origin a9745db86dc3b942a435a989e449b3cce88defa6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-sugarjar
 * [new ref]         a9745db86dc3b942a435a989e449b3cce88defa6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a9745db Update for upstream 4.0.0