$ git clone -n https://src.fedoraproject.org/rpms/gnutls.git /var/lib/mock/f42-build-side-1-3585048-46902/root/chroot_tmpdir/scmroot/gnutls
Cloning into '/var/lib/mock/f42-build-side-1-3585048-46902/root/chroot_tmpdir/scmroot/gnutls'...
$ git fetch origin fa4b79c7e3e1addadc8b3b8b813659e6ea44a219:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnutls
 * [new ref]         fa4b79c7e3e1addadc8b3b8b813659e6ea44a219 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fa4b79c Bump for gmp build