Fixes #404: Use log.rs and a file-per-thread logger instead of the dbg! macro;

lib/filetests/src/concurrent.rs

@@ -3,7 +3,9 @@
 //! This module provides the `ConcurrentRunner` struct which uses a pool of threads to run tests
 //! concurrently.
 
+use cranelift_codegen::dbg::LOG_FILENAME_PREFIX;
 use cranelift_codegen::timing;
+use file_per_thread_logger;
 use num_cpus;
 use std::panic::catch_unwind;
 use std::path::{Path, PathBuf};
@@ -100,6 +102,7 @@ fn heartbeat_thread(replies: Sender<Reply>) -> thread::JoinHandle<()> {
     thread::Builder::new()
         .name("heartbeat".to_string())
         .spawn(move || {
+            file_per_thread_logger::initialize(LOG_FILENAME_PREFIX);
             while replies.send(Reply::Tick).is_ok() {
                 thread::sleep(Duration::from_secs(1));
             }
@@ -116,6 +119,7 @@ fn worker_thread(
     thread::Builder::new()
         .name(format!("worker #{}", thread_num))
         .spawn(move || {
+            file_per_thread_logger::initialize(LOG_FILENAME_PREFIX);
             loop {
                 // Lock the mutex only long enough to extract a request.
                 let Request(jobid, path) = match requests.lock().unwrap().recv() {
@@ -140,7 +144,7 @@ fn worker_thread(
                 });
 
                 if let Err(ref msg) = result {
-                    dbg!("FAIL: {}", msg);
+                    error!("FAIL: {}", msg);
                 }
 
                 replies.send(Reply::Done { jobid, result }).unwrap();