$ git clone -n https://github.com/xcp-ng-rpms/gnutls.git /var/lib/mock/v8.3-u-pcoval2-10884-29382/root/chroot_tmpdir/scmroot/gnutls
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10884-29382/root/chroot_tmpdir/scmroot/gnutls'...
$ git fetch origin 12269d50f06c3b9a40eec65d018a707c034c6fdf:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/gnutls
 * [new ref]         12269d50f06c3b9a40eec65d018a707c034c6fdf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 12269d5 bump release for test build