$ git clone -n https://github.com/xcp-ng-rpms/gnutls.git /var/lib/mock/v8.3-u-pcoval2-10374-28936/root/chroot_tmpdir/scmroot/gnutls
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10374-28936/root/chroot_tmpdir/scmroot/gnutls'...
$ git fetch origin f9fccc0cc0b2469638a56a45b07afc3fea8865b2:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/gnutls
 * [new ref]         f9fccc0cc0b2469638a56a45b07afc3fea8865b2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f9fccc0 bump release for test build