$ git clone -n https://src.fedoraproject.org/rpms/trademgen.git /var/lib/mock/f40-build-804422-144517/root/chroot_tmpdir/scmroot/trademgen
Cloning into '/var/lib/mock/f40-build-804422-144517/root/chroot_tmpdir/scmroot/trademgen'...
$ git fetch origin 612704b85b20dffdbdc2d884f0a0fc0a5121afa2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/trademgen
 * [new ref]         612704b85b20dffdbdc2d884f0a0fc0a5121afa2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 612704b Upstream upgrade