message: fix evaluate var
diff: @@ -348,6 +348,8 @@ impl Variable {
  LookupSorted(i) => l.map(|l| l.sorted[i]),
  LookupAggreg => l.map(|l| l.aggreg),
  LookupTable => l.map(|l| l.table),
  + Index(GateType::Poseidon) => Ok(evals.poseidon_selector),
  + Index(GateType::Generic) => Ok(evals.generic_selector),
  Coefficient(_) | LookupKindIndex(_) | Index(_) =>
  Err("Cannot get index evaluation (should have been linearized away)")
  }
  