fn try_execute_query<Q, Qcx, const INCR: bool>(
    query: Q,
    qcx: Qcx,
    span: Span,
    key: Q::Key,
    dep_node: Option<DepNode>
) -> (Q::Value, Option<DepNodeIndex>)
where Q: QueryConfig<Qcx>, Qcx: QueryContext,