syntax_data: {"ast_node_type":"impl","tokens":[{"end":95,"kind":"keyword","start":0,"text":"bug!(\"impl"}]}
source_snippet:                 bug!("impl {impl_def_id:?} was matchable against {predicate:?} but now is not")
context_before:                 let predicate = self.infcx.resolve_vars_if_possible(obligation.predicate);
context_after:             }