chore: errors when don't implement Display trait, instead a formatter provided by std::fmt::Debug

src/lib.rs

@@ -352,7 +352,7 @@ async fn metrics_handler() -> Result<impl Reply, Rejection> {
 
     let mut buffer = Vec::new();
     if let Err(e) = encoder.encode(&REGISTRY.gather(), &mut buffer) {
-        error!("could not encode custom metrics: {}", e);
+        error!("could not encode custom metrics: {:?}", e);
     };
     let res = match String::from_utf8(buffer.clone()) {
         Ok(v) => v,