unwrap_err() now uses Debug

src/options.rs

@@ -330,8 +330,6 @@ mod test {
     use super::Misfire;
     use super::Misfire::*;
 
-    use std::fmt;
-
     fn is_helpful(misfire: Result<Options, Misfire>) -> bool {
         match misfire {
             Err(Help(_)) => true,
@@ -339,12 +337,6 @@ mod test {
         }
     }
 
-    impl fmt::Display for Options {
-        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-                write!(f, "{:?}", self)
-        }
-    }
-
     #[test]
     fn help() {
         let opts = Options::getopts(&[ "--help".to_string() ]);