report serde parse errors to stderr

src/bin/client-demo.rs

@@ -43,7 +43,10 @@ fn main() {
     if matches.opt_present("t") {
         threads = matches.opt_str("t").unwrap().parse().expect("integer");
     }
-    let mint: Mint = serde_json::from_reader(stdin()).unwrap();
+    let mint: Mint = serde_json::from_reader(stdin()).unwrap_or_else(|e| {
+        eprintln!("failed to parse json: {}", e);
+        exit(1);
+    });
     let mint_keypair = mint.keypair();
     let mint_pubkey = mint.pubkey();
 

src/bin/genesis-demo.rs

@@ -8,13 +8,17 @@ use solana::mint::Mint;
 use solana::signature::{KeyPair, KeyPairUtil, PublicKey};
 use solana::transaction::Transaction;
 use std::io::stdin;
+use std::process::exit;
 
 fn transfer(from: &KeyPair, (to, tokens): (PublicKey, i64), last_id: Hash) -> Event {
     Event::Transaction(Transaction::new(from, to, tokens, last_id))
 }
 
 fn main() {
-    let mint: Mint = serde_json::from_reader(stdin()).unwrap();
+    let mint: Mint = serde_json::from_reader(stdin()).unwrap_or_else(|e| {
+        eprintln!("failed to parse json: {}", e);
+        exit(1);
+    });
     let mut entries = mint.create_entries();
 
     let from = mint.keypair();
@@ -25,6 +29,10 @@ fn main() {
     entries.push(create_entry(&seed, 0, events));
 
     for entry in entries {
-        println!("{}", serde_json::to_string(&entry).unwrap());
+        let serialized = serde_json::to_string(&entry).unwrap_or_else(|e| {
+            eprintln!("failed to serialize: {}", e);
+            exit(1);
+        });
+        println!("{}", serialized);
     }
 }

src/bin/genesis.rs

@@ -5,10 +5,18 @@ extern crate solana;
 
 use solana::mint::Mint;
 use std::io::stdin;
+use std::process::exit;
 
 fn main() {
-    let mint: Mint = serde_json::from_reader(stdin()).unwrap();
+    let mint: Mint = serde_json::from_reader(stdin()).unwrap_or_else(|e| {
+        eprintln!("failed to parse json: {}", e);
+        exit(1);
+    });
     for x in mint.create_entries() {
-        println!("{}", serde_json::to_string(&x).unwrap());
+        let serialized = serde_json::to_string(&x).unwrap_or_else(|e| {
+            eprintln!("failed to serialize: {}", e);
+            exit(1);
+        });
+        println!("{}", serialized);
     }
 }

src/bin/mint.rs

@@ -3,6 +3,7 @@ extern crate solana;
 
 use solana::mint::Mint;
 use std::io;
+use std::process::exit;
 
 fn main() {
     let mut input_text = String::new();
@@ -11,5 +12,9 @@ fn main() {
     let tokens = trimmed.parse::<i64>().unwrap();
 
     let mint = Mint::new(tokens);
-    println!("{}", serde_json::to_string(&mint).unwrap());
+    let serialized = serde_json::to_string(&mint).unwrap_or_else(|e| {
+        eprintln!("failed to serialize: {}", e);
+        exit(1);
+    });
+    println!("{}", serialized);
 }

src/bin/testnode.rs

@@ -33,10 +33,12 @@ fn main() {
     }
     let addr = format!("0.0.0.0:{}", port);
     let stdin = io::stdin();
-    let mut entries = stdin
-        .lock()
-        .lines()
-        .map(|line| serde_json::from_str(&line.unwrap()).unwrap());
+    let mut entries = stdin.lock().lines().map(|line| {
+        serde_json::from_str(&line.unwrap()).unwrap_or_else(|e| {
+            eprintln!("failed to parse json: {}", e);
+            exit(1);
+        })
+    });
 
     // The first item in the ledger is required to be an entry with zero num_hashes,
     // which implies its id can be used as the ledger's seed.