syntax_data: {"ast_node_type":"variable","tokens":[{"end":56,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let target = self.infcx.shallow_resolve(target);
context_before:         let target = obligation.predicate.skip_binder().trait_ref.args.type_at(1);
context_after:         debug!(?source, ?target, "confirm_builtin_unsize_candidate");