Function parse_error_report 

pub fn parse_error_report(file: &Path, text: &str, pe: &ParseError) -> String

Everything largo writes to standard error for a program the compiler rejects with pe, whose span is in text, the text of file: the error: block with the explanation, the excerpt and the --> file:line:col, without terminal styles. Every backend largo drives reports a rejected program in exactly these bytes, and the tier-parity census holds the backends it drives in-process to them too.