From 6b8919b37be15cc8bab9b1baf45f6166c5b0326a Mon Sep 17 00:00:00 2001
From: Jonathan Kelley <jkelleyrtp@gmail.com>
Date: Thu, 15 May 2025 14:16:59 +0200
Subject: [PATCH] fix stdin handling for the tw watcher (#4119)

---
 packages/cli/src/serve/mod.rs    |  2 +-
 packages/cli/src/serve/runner.rs |  9 ++++++---
 packages/cli/src/tailwind.rs     | 10 ++++++++--
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/packages/cli/src/serve/mod.rs b/packages/cli/src/serve/mod.rs
index 3a6238344..5fa390967 100644
--- a/packages/cli/src/serve/mod.rs
+++ b/packages/cli/src/serve/mod.rs
@@ -203,7 +203,7 @@ pub(crate) async fn serve_all(args: ServeArgs, tracer: &mut TraceController) ->
             }
 
             ServeUpdate::Exit { error } => {
-                _ = builder.cleanup_all().await;
+                _ = builder.shutdown().await;
                 _ = devserver.shutdown().await;
 
                 match error {
diff --git a/packages/cli/src/serve/runner.rs b/packages/cli/src/serve/runner.rs
index 610ae64ae..4598517c7 100644
--- a/packages/cli/src/serve/runner.rs
+++ b/packages/cli/src/serve/runner.rs
@@ -74,7 +74,7 @@ pub(crate) struct AppServer {
     pub(crate) cross_origin_policy: bool,
 
     // Additional plugin-type tools
-    pub(crate) _tw_watcher: tokio::task::JoinHandle<Result<()>>,
+    pub(crate) tw_watcher: tokio::task::JoinHandle<Result<()>>,
 }
 
 pub(crate) struct CachedFile {
@@ -186,7 +186,7 @@ impl AppServer {
             _force_sequential: force_sequential,
             cross_origin_policy,
             fullstack,
-            _tw_watcher: tw_watcher,
+            tw_watcher,
         };
 
         // Only register the hot-reload stuff if we're watching the filesystem
@@ -564,7 +564,7 @@ impl AppServer {
     }
 
     /// Shutdown all the running processes
-    pub(crate) async fn cleanup_all(&mut self) -> Result<()> {
+    pub(crate) async fn shutdown(&mut self) -> Result<()> {
         self.client.soft_kill().await;
 
         if let Some(server) = self.server.as_mut() {
@@ -588,6 +588,9 @@ impl AppServer {
             }
         }
 
+        // force the tailwind watcher to stop - if we don't, it eats our stdin
+        self.tw_watcher.abort();
+
         Ok(())
     }
 
diff --git a/packages/cli/src/tailwind.rs b/packages/cli/src/tailwind.rs
index e907ffccf..4cd111136 100644
--- a/packages/cli/src/tailwind.rs
+++ b/packages/cli/src/tailwind.rs
@@ -34,8 +34,12 @@ impl TailwindCli {
                 tailwind.install_github().await?;
             }
 
-            let proc = tailwind.watch(&manifest_dir, input_path, output_path)?;
-            proc.wait_with_output().await?;
+            // the tw watcher blocks on stdin, and `.wait()` will drop stdin
+            // unfortunately the tw watcher just deadlocks in this case, so we take the stdin manually
+            let mut proc = tailwind.watch(&manifest_dir, input_path, output_path)?;
+            let stdin = proc.stdin.take();
+            proc.wait().await?;
+            drop(stdin);
 
             Ok(())
         })
@@ -107,6 +111,8 @@ impl TailwindCli {
             .arg("--output")
             .arg(output_path)
             .arg("--watch")
+            .kill_on_drop(true)
+            .stdin(Stdio::piped())
             .stdout(Stdio::null())
             .stderr(Stdio::null())
             .spawn()?;