syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"Err(SelectionError::Overflow(OverflowError::Canonical))"}]}
source_snippet:             Err(SelectionError::Overflow(OverflowError::Canonical)) => {
context_before:         let candidate = match self.select_from_obligation(obligation) {
context_after:                 // In standard mode, overflow must have been caught and reported