$ git clone -n https://src.fedoraproject.org/rpms/grilo.git /var/lib/mock/f42-build-side-1-3587166-46928/root/chroot_tmpdir/scmroot/grilo
Cloning into '/var/lib/mock/f42-build-side-1-3587166-46928/root/chroot_tmpdir/scmroot/grilo'...
$ git fetch origin 8942fa41ea1d2a7a585ce1a0f1e7d0e1df625d2a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/grilo
 * [new ref]         8942fa41ea1d2a7a585ce1a0f1e7d0e1df625d2a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8942fa4 Update to 0.3.19