$ git clone -n https://github.com/xcp-ng-rpms/gnutls.git /var/lib/mock/v8.3-u-pcoval1-11079-29514/root/chroot_tmpdir/scmroot/gnutls
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11079-29514/root/chroot_tmpdir/scmroot/gnutls'...
$ git fetch origin aee7515f9aa1fba4c62d15c72370c80ba662ab86:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/gnutls
 * [new ref]         aee7515f9aa1fba4c62d15c72370c80ba662ab86 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aee7515 bump release for test build