$ git clone -n https://src.fedoraproject.org/rpms/diffutils.git /var/lib/mock/f41-build-825511-154514/root/chroot_tmpdir/scmroot/diffutils
Cloning into '/var/lib/mock/f41-build-825511-154514/root/chroot_tmpdir/scmroot/diffutils'...
$ git fetch origin efeeb64f37b6f1b38861fbb4d3a463ed7b6553fa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/diffutils
 * [new ref]         efeeb64f37b6f1b38861fbb4d3a463ed7b6553fa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at efeeb64 refresh patch for 'cmp -s'