$ git clone -n https://src.fedoraproject.org/rpms/gnutls.git /var/lib/mock/f42-build-side-1-3588876-46951/root/chroot_tmpdir/scmroot/gnutls
Cloning into '/var/lib/mock/f42-build-side-1-3588876-46951/root/chroot_tmpdir/scmroot/gnutls'...
$ git fetch origin 5cccaeedc8f732416ced2b743c65d6897341e891:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnutls
 * [new ref]         5cccaeedc8f732416ced2b743c65d6897341e891 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5cccaee Update to 3.8.10 upstream release