$ git clone -n https://src.fedoraproject.org/rpms/sysstat.git /var/lib/mock/f42-build-889824-189296/root/chroot_tmpdir/scmroot/sysstat
Cloning into '/var/lib/mock/f42-build-889824-189296/root/chroot_tmpdir/scmroot/sysstat'...
$ git fetch origin 28a95f5b4b403b0157aa04e7c9453001d8196b85:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/sysstat
 * [new ref]         28a95f5b4b403b0157aa04e7c9453001d8196b85 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 28a95f5 rebase to latest upstream release