fix: drop bundler lock before awaiting coordinator in close() to prevent deadlock

Copilot · hyf0 · Copilot · commit d34c891fa94f · 2026-03-07T02:07:51.000Z
Co-authored-by: hyf0 &lt;49502170+hyf0@users.noreply.github.com&gt;
diff --git a/crates/rolldown_dev/src/dev_engine.rs b/crates/rolldown_dev/src/dev_engine.rs
@@ -362,9 +362,14 @@ impl DevEngine {
       .map_err_to_unhandleable()
       .context("DevEngine: failed to send Close message to coordinator - coordinator may have already terminated")?;
 
-    // Close the bundler (calls `closeBundle` plugin hook)
-    let mut bundler = self.bundler.lock().await;
-    bundler.close().await?;
+    // Close the bundler (calls `closeBundle` plugin hook).
+    // The bundler lock MUST be released before waiting for the coordinator below.
+    // Otherwise we'd deadlock: the coordinator's Close handler waits for any running
+    // bundling task to finish, and that task may need to acquire the bundler lock.
+    {
+      let mut bundler = self.bundler.lock().await;
+      bundler.close().await?;
+    }
 
     // Wait for coordinator to close (coordinator handles watcher cleanup)
     let coordinator_state = self.coordinator_state.lock().await;
diff --git a/crates/rolldown_testing/src/integration_test.rs b/crates/rolldown_testing/src/integration_test.rs
@@ -366,7 +366,10 @@ impl IntegrationTest {
       // Explicitly close the dev engine to shut down the background coordinator task.
       // Without this, the coordinator task would persist across tests under the shared runtime.
       if let Err(err) = dev_engine.close().await {
-        panic!("Failed to close dev_engine for integration test `{debug_title}`: {err:#?}");
+        panic!(
+          "Failed to close dev_engine for integration test in `{}` (title: `{debug_title}`): {err:#?}",
+          test_folder_path.display()
+        );
       }
     }
 

Original file line number	Diff line number	Diff line change
`@@ -366,7 +366,10 @@ impl IntegrationTest {`
`366`	`366`	`// Explicitly close the dev engine to shut down the background coordinator task.`
`367`	`367`	`// Without this, the coordinator task would persist across tests under the shared runtime.`
`368`	`368`	`if let Err(err) = dev_engine.close().await {`
`369`		- panic!("Failed to close dev_engine for integration test `{debug_title}`: {err:#?}");
	`369`	`+ panic!(`
	`370`	+ "Failed to close dev_engine for integration test in `{}` (title: `{debug_title}`): {err:#?}",
	`371`	`+ test_folder_path.display()`
	`372`	`+ );`
`370`	`373`	`}`
`371`	`374`	`}`
`372`	`375`