message: Implement Fail for EvalPrintError
diff: @@ -222,9 +222,12 @@ enum ControlFlow {
  Continue(Option<Context>),
  }
  +#[derive(Debug, Fail)]
  enum EvalPrintError {
  + #[fail(display = "Parse error")]
  Parse(Vec<parse::ParseError>),
  - Type(semantics::TypeError),
  + #[fail(display = "Type error: {}", _0)]
  + Type(#[cause] semantics::TypeError),
  }
  impl From<parse::ParseError> for EvalPrintError {
  