Switch from std::sync::mpsc to crossbeam-channel

This lets us avoid rust-lang/rust#39364, which
could potentially be seen now that we're using recv_timeout().

Cargo.toml

@@ -49,6 +49,7 @@ dirs-next = "2.0"
 normpath = "0.3"
 chrono = "0.4"
 once_cell = "1.8.0"
+crossbeam-channel = "0.5.1"
 
 [dependencies.clap]
 version = "2.31.3"

src/exec/job.rs

@@ -1,7 +1,8 @@
 use std::path::PathBuf;
-use std::sync::mpsc::Receiver;
 use std::sync::{Arc, Mutex};
 
+use crossbeam_channel::Receiver;
+
 use crate::error::print_error;
 use crate::exit_codes::{merge_exitcodes, ExitCode};
 use crate::walk::WorkerResult;

src/walk.rs

@@ -4,13 +4,13 @@ use std::io;
 use std::mem;
 use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::mpsc::{channel, Receiver, RecvTimeoutError, Sender};
 use std::sync::{Arc, Mutex};
 use std::thread;
 use std::time::{Duration, Instant};
 use std::{borrow::Cow, io::Write};
 
 use anyhow::{anyhow, Result};
+use crossbeam_channel::{unbounded, Receiver, RecvTimeoutError, Sender};
 use ignore::overrides::OverrideBuilder;
 use ignore::{self, WalkBuilder};
 use once_cell::unsync::OnceCell;
@@ -55,7 +55,7 @@ pub fn scan(path_vec: &[PathBuf], pattern: Arc<Regex>, config: Arc<Config>) -> R
     let first_path_buf = path_iter
         .next()
         .expect("Error: Path vector can not be empty");
-    let (tx, rx) = channel();
+    let (tx, rx) = unbounded();
 
     let mut override_builder = OverrideBuilder::new(first_path_buf.as_path());
 
@@ -219,11 +219,7 @@ impl<W: Write> ReceiverBuffer<W> {
         match self.mode {
             ReceiverMode::Buffering => {
                 // Wait at most until we should switch to streaming
-                let now = Instant::now();
-                self.deadline
-                    .checked_duration_since(now)
-                    .ok_or(RecvTimeoutError::Timeout)
-                    .and_then(|t| self.rx.recv_timeout(t))
+                self.rx.recv_deadline(self.deadline)
             }
             ReceiverMode::Streaming => {
                 // Wait however long it takes for a result