format!("{:?}", self)
}
+ /// This method tries to recover the query key from the given `DepNode`,
+ /// something which is needed when forcing `DepNode`s during red-green
+ /// evaluation. The query system will only call this method if
+ /// `CAN_RECONSTRUCT_QUERY_KEY` is `true`.
+ /// It is always valid to return `None` here, in which case incremental
+ /// compilation will treat the query as having changed instead of forcing it.
fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self>;
}