$ git clone -n https://src.fedoraproject.org/rpms/testcloud.git /var/lib/mock/f39-build-1761043-41496/root/chroot_tmpdir/scmroot/testcloud
Cloning into '/var/lib/mock/f39-build-1761043-41496/root/chroot_tmpdir/scmroot/testcloud'...
$ git fetch origin d721d4b198bb01e2d45dfced1ed04a1be65e515c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/testcloud
 * [new ref]         d721d4b198bb01e2d45dfced1ed04a1be65e515c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d721d4b Release 0.9.10