implement Debug for ErrorKind

src/error.rs

@@ -66,7 +66,7 @@ impl StdError for Error {}
 
 impl Display for Error {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        self.kind.fmt(f)
+        std::fmt::Display::fmt(&self.kind, f)
     }
 }
 
@@ -76,6 +76,12 @@ impl Debug for Error {
     }
 }
 
+impl Debug for ErrorKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(self, f)
+    }
+}
+
 impl Display for ErrorKind {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "error: ")?;