From 34c44ffb6bea93c844f1da1f529fda18e86df973 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sat, 16 Sep 2023 13:26:45 -0600
Subject: [PATCH] Propagate thread creation error in flock

---
 src/flock.rs | 19 ++++++++++---------
 src/run.rs   |  2 +-
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/flock.rs b/src/flock.rs
index bd6a0f9..9cb3fba 100644
--- a/src/flock.rs
+++ b/src/flock.rs
@@ -1,3 +1,4 @@
+use crate::error::Result;
 use once_cell::sync::OnceCell;
 use std::fs::{self, File, OpenOptions};
 use std::io;
@@ -32,11 +33,11 @@ enum FileLock {
 }
 
 impl Lock {
-    pub fn acquire(path: impl AsRef<Path>) -> Self {
-        Lock {
+    pub fn acquire(path: impl AsRef<Path>) -> Result<Self> {
+        Ok(Lock {
             intraprocess_guard: Guard::acquire(),
-            lockfile: FileLock::acquire(path),
-        }
+            lockfile: FileLock::acquire(path)?,
+        })
     }
 }
 
@@ -51,18 +52,18 @@ impl Guard {
 }
 
 impl FileLock {
-    fn acquire(path: impl AsRef<Path>) -> Self {
+    fn acquire(path: impl AsRef<Path>) -> Result<Self> {
         let path = path.as_ref().to_owned();
         let lockfile = match create(&path) {
-            None => return FileLock::NotLocked,
+            None => return Ok(FileLock::NotLocked),
             Some(lockfile) => lockfile,
         };
         let done = Arc::new(AtomicBool::new(false));
-        thread::spawn({
+        thread::Builder::new().spawn({
             let done = Arc::clone(&done);
             move || poll(lockfile, done)
-        });
-        FileLock::Locked { path, done }
+        })?;
+        Ok(FileLock::Locked { path, done })
     }
 }
 
diff --git a/src/run.rs b/src/run.rs
index e2686a5..f26d6a5 100644
--- a/src/run.rs
+++ b/src/run.rs
@@ -52,7 +52,7 @@ impl Runner {
 
         let (project, _lock) = (|| {
             let mut project = self.prepare(&tests)?;
-            let lock = Lock::acquire(path!(project.dir / ".lock"));
+            let lock = Lock::acquire(path!(project.dir / ".lock"))?;
             self.write(&mut project)?;
             Ok((project, lock))
         })()