syntax_data: {"ast_node_type":"variable","tokens":[{"end":64,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let result = D::on_fixpoint_overflow(cx, input);
context_before:                 debug!("canonical cycle overflow");
context_after:                 self.rebase_provisional_cache_entries(&stack_entry, |input, _| {