Fix some nightly warnings (#5093)

ONCE_INIT => Once::new
Box<Error> => Box<dyn Error>

logger/src/lib.rs

@@ -2,9 +2,9 @@
 //! `setup()` may be called multiple times.
 
 use env_logger;
-use std::sync::{Once, ONCE_INIT};
+use std::sync::Once;
 
-static INIT: Once = ONCE_INIT;
+static INIT: Once = Once::new();
 
 /// Setup function that is only run once, even if called multiple times.
 pub fn setup() {

metrics/src/counter.rs

@@ -62,7 +62,7 @@ macro_rules! inc_new_counter {
         if log_enabled!($level) {
             static mut INC_NEW_COUNTER: $crate::counter::Counter =
                 create_counter!($name, $lograte, $metricsrate);
-            static INIT_HOOK: std::sync::Once = std::sync::ONCE_INIT;
+            static INIT_HOOK: std::sync::Once = std::sync::Once::new();
             unsafe {
                 INIT_HOOK.call_once(|| {
                     INC_NEW_COUNTER.init();
@@ -197,11 +197,11 @@ mod tests {
     use serial_test_derive::serial;
     use std::env;
     use std::sync::atomic::Ordering;
-    use std::sync::{Once, RwLock, ONCE_INIT};
+    use std::sync::{Once, RwLock};
 
     fn get_env_lock() -> &'static RwLock<()> {
         static mut ENV_LOCK: Option<RwLock<()>> = None;
-        static INIT_HOOK: Once = ONCE_INIT;
+        static INIT_HOOK: Once = Once::new();
 
         unsafe {
             INIT_HOOK.call_once(|| {

metrics/src/metrics.rs

@@ -8,7 +8,7 @@ use solana_sdk::hash::hash;
 use solana_sdk::timing;
 use std::collections::HashMap;
 use std::sync::mpsc::{channel, Receiver, RecvTimeoutError, Sender};
-use std::sync::{Arc, Barrier, Mutex, Once, ONCE_INIT};
+use std::sync::{Arc, Barrier, Mutex, Once};
 use std::thread;
 use std::time::{Duration, Instant};
 use std::{cmp, env};
@@ -379,7 +379,7 @@ impl Drop for MetricsAgent {
 }
 
 fn get_singleton_agent() -> Arc<Mutex<MetricsAgent>> {
-    static INIT: Once = ONCE_INIT;
+    static INIT: Once = Once::new();
     static mut AGENT: Option<Arc<Mutex<MetricsAgent>>> = None;
     unsafe {
         INIT.call_once(|| AGENT = Some(Arc::new(Mutex::new(MetricsAgent::default()))));
@@ -430,7 +430,7 @@ pub fn flush() {
 /// Hook the panic handler to generate a data point on each panic
 pub fn set_panic_hook(program: &'static str) {
     use std::panic;
-    static SET_HOOK: Once = ONCE_INIT;
+    static SET_HOOK: Once = Once::new();
     SET_HOOK.call_once(|| {
         let default_hook = panic::take_hook();
         panic::set_hook(Box::new(move |ono| {

sdk/src/pubkey.rs

@@ -69,7 +69,7 @@ impl fmt::Display for Pubkey {
     }
 }
 
-pub fn write_pubkey(outfile: &str, pubkey: Pubkey) -> Result<(), Box<error::Error>> {
+pub fn write_pubkey(outfile: &str, pubkey: Pubkey) -> Result<(), Box<dyn error::Error>> {
     let printable = format!("{}", pubkey);
     let serialized = serde_json::to_string(&printable)?;
 
@@ -82,7 +82,7 @@ pub fn write_pubkey(outfile: &str, pubkey: Pubkey) -> Result<(), Box<error::Erro
     Ok(())
 }
 
-pub fn read_pubkey(infile: &str) -> Result<Pubkey, Box<error::Error>> {
+pub fn read_pubkey(infile: &str) -> Result<Pubkey, Box<dyn error::Error>> {
     let f = File::open(infile.to_string())?;
     let printable: String = serde_json::from_reader(f)?;
     Ok(Pubkey::from_str(&printable)?)
@@ -166,7 +166,7 @@ mod tests {
     }
 
     #[test]
-    fn test_read_write_pubkey() -> Result<(), Box<error::Error>> {
+    fn test_read_write_pubkey() -> Result<(), Box<dyn error::Error>> {
         let filename = "test_pubkey.json";
         let pubkey = Pubkey::new_rand();
         write_pubkey(filename, pubkey)?;

sdk/src/signature.rs

@@ -118,7 +118,7 @@ impl KeypairUtil for Keypair {
     }
 }
 
-pub fn read_keypair(path: &str) -> Result<Keypair, Box<error::Error>> {
+pub fn read_keypair(path: &str) -> Result<Keypair, Box<dyn error::Error>> {
     let file = File::open(path.to_string())?;
     let bytes: Vec<u8> = serde_json::from_reader(file)?;
     let keypair = Keypair::from_bytes(&bytes)
@@ -126,7 +126,7 @@ pub fn read_keypair(path: &str) -> Result<Keypair, Box<error::Error>> {
     Ok(keypair)
 }
 
-pub fn gen_keypair_file(outfile: &str) -> Result<String, Box<error::Error>> {
+pub fn gen_keypair_file(outfile: &str) -> Result<String, Box<dyn error::Error>> {
     let keypair_bytes = Keypair::new().to_bytes();
     let serialized = serde_json::to_string(&keypair_bytes.to_vec())?;