use thiserror

Cargo.lock

@@ -1864,6 +1864,7 @@ dependencies = [
  "phf_codegen",
  "rustpython-ast",
  "rustpython-compiler-core",
+ "thiserror",
  "tiny-keccak",
  "unic-emoji-char",
  "unic-ucd-ident",

compiler/core/src/error.rs

@@ -16,14 +16,7 @@ impl<T> std::ops::Deref for BaseError<T> {
     }
 }
 
-impl<T> std::error::Error for BaseError<T>
-where
-    T: std::fmt::Display + std::fmt::Debug,
-{
-    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
-        None
-    }
-}
+impl<T> std::error::Error for BaseError<T> where T: std::fmt::Display + std::fmt::Debug {}
 
 impl<T> Display for BaseError<T>
 where

compiler/parser/Cargo.toml

@@ -28,6 +28,7 @@ phf = "0.10.1"
 unic-emoji-char = "0.9.0"
 unic-ucd-ident  = "0.9.0"
 unicode_names2 = "0.5.0"
+thiserror = "1.0"
 
 [dev-dependencies]
 insta = "1.14.0"

compiler/parser/src/error.rs

@@ -3,7 +3,7 @@
 
 use crate::{ast::Location, token::Tok};
 use lalrpop_util::ParseError as LalrpopError;
-use std::{error::Error, fmt};
+use std::fmt;
 
 /// Represents an error during lexical scanning.
 #[derive(Debug, PartialEq)]
@@ -119,7 +119,7 @@ impl From<FStringError> for LalrpopError<Location, Tok, LexicalError> {
 /// Represents an error during parsing
 pub type ParseError = rustpython_compiler_core::BaseError<ParseErrorType>;
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, thiserror::Error)]
 pub enum ParseErrorType {
     /// Parser encountered an unexpected end of input
     Eof,
@@ -194,8 +194,6 @@ impl fmt::Display for ParseErrorType {
     }
 }
 
-impl Error for ParseErrorType {}
-
 impl ParseErrorType {
     pub fn is_indentation_error(&self) -> bool {
         match self {