Suppress panicking when pipe closed

src/gpu.rs

@@ -39,7 +39,7 @@ impl Gpu {
             .build()?;
 
         let device = pro_que.device();
-        eprintln!(
+        println!(
             "Initializing GPU: {} {}",
             device.vendor().unwrap_or_else(|_| "[unknown]".into()),
             device.name().unwrap_or_else(|_| "[unknown]".into())

src/main.rs

@@ -14,6 +14,7 @@ extern crate serde_json;
 
 mod gpu;
 
+use std::io::{self, Write};
 use std::u64;
 use std::num::Wrapping;
 use std::collections::VecDeque;
@@ -274,9 +275,10 @@ impl RpcService {
                 Box::new(self.generate_work(root, difficulty).then(move |res| match res {
                     Ok(work) => {
                         let end = PreciseTime::now();
-                        println!("work_generate completed in {}ms for difficulty {:#x}",
+                        writeln!(io::stdout(), "work_generate completed in {}ms for difficulty {:#x}",
                             start.to(end).num_milliseconds(),
-                            difficulty);
+                            difficulty)
+                            .unwrap_or(());
                         let result_difficulty = work_value(root, work);
                         Ok((
                             StatusCode::Ok,
@@ -302,12 +304,12 @@ impl RpcService {
                 }))
             }
             RpcCommand::WorkCancel(root) => {
-                println!("Received work_cancel");
+                writeln!(io::stdout(), "Received work_cancel").unwrap_or(());
                 self.cancel_work(root);
                 Box::new(Box::new(future::ok((StatusCode::Ok, json!({})))))
             }
             RpcCommand::WorkValidate(root, work, difficulty) => {
-                println!("Received work_validate");
+                writeln!(io::stdout(), "Received work_validate").unwrap_or(());
                 let (valid, result_difficulty) = work_valid(root, work, difficulty);
                 Box::new(future::ok((
                     StatusCode::Ok,