fix(cli,core): stop dev workers spinning at 100% CPU after parent CLI disconnect

.changeset/dev-worker-disconnect-loop.md

@@ -0,0 +1,6 @@
+---
+"@trigger.dev/core": patch
+"trigger.dev": patch
+---
+
+Fix dev workers spinning at 100% CPU after the parent CLI disconnects. Orphaned `trigger-dev-run-worker` (and indexer) processes were caught in an `uncaughtException` feedback loop: a periodic IPC send via `process.send` would throw `ERR_IPC_CHANNEL_CLOSED` once the parent closed the channel, which re-entered the same handler that itself called `process.send`, scheduled via `setImmediate` and amplified by source-map-support's `prepareStackTrace`. Fixed by (1) silently dropping packets in `ZodIpcConnection` when the channel is disconnected, (2) adding a `process.on("disconnect", ...)` handler in dev workers so they exit cleanly when the CLI closes the IPC channel, and (3) wrapping all `uncaughtException`-path `process.send` calls in a `safeSend` guard that checks `process.connected` and swallows synchronous throws.

packages/cli-v3/src/entryPoints/dev-index-worker.ts

@@ -27,30 +27,45 @@ sourceMapSupport.install({
   hookRequire: false,
 });
 
+// If the parent CLI closes the IPC channel, exit cleanly instead of being
+// re-parented to init and busy-looping on `process.send` against a dead channel.
+process.on("disconnect", () => {
+  process.exit(0);
+});
+
+function safeSend(message: unknown) {
+  if (!process.connected || !process.send) {
+    return;
+  }
+  try {
+    process.send(message);
+  } catch {
+    // swallow: a throw here would re-enter this handler and busy-loop the worker
+  }
+}
+
 process.on("uncaughtException", function (error, origin) {
   if (error instanceof Error) {
-    process.send &&
-      process.send({
-        type: "UNCAUGHT_EXCEPTION",
-        payload: {
-          error: { name: error.name, message: error.message, stack: error.stack },
-          origin,
-        },
-        version: "v1",
-      });
+    safeSend({
+      type: "UNCAUGHT_EXCEPTION",
+      payload: {
+        error: { name: error.name, message: error.message, stack: error.stack },
+        origin,
+      },
+      version: "v1",
+    });
   } else {
-    process.send &&
-      process.send({
-        type: "UNCAUGHT_EXCEPTION",
-        payload: {
-          error: {
-            name: "Error",
-            message: typeof error === "string" ? error : JSON.stringify(error),
-          },
-          origin,
+    safeSend({
+      type: "UNCAUGHT_EXCEPTION",
+      payload: {
+        error: {
+          name: "Error",
+          message: typeof error === "string" ? error : JSON.stringify(error),
         },
-        version: "v1",
-      });
+        origin,
+      },
+      version: "v1",
+    });
   }
 });
 
@@ -183,7 +198,7 @@ await sendMessageInCatalog(
     importErrors,
   },
   async (msg) => {
-    process.send?.(msg);
+    safeSend(msg);
   }
 ).catch((err) => {
   if (err instanceof ZodSchemaParsedError) {

packages/cli-v3/src/entryPoints/dev-run-worker.ts

@@ -77,37 +77,53 @@ sourceMapSupport.install({
   hookRequire: false,
 });
 
+// If the parent CLI closes the IPC channel (process restart, crash, lost
+// handle), exit cleanly instead of being re-parented to init and busy-looping
+// on `process.send` that throws against a dead channel.
+process.on("disconnect", () => {
+  process.exit(0);
+});
+
+function safeSend(message: unknown) {
+  if (!process.connected || !process.send) {
+    return;
+  }
+  try {
+    process.send(message);
+  } catch {
+    // swallow: a throw here would re-enter this handler and busy-loop the worker
+  }
+}
+
 process.on("uncaughtException", function (error, origin) {
   logError("Uncaught exception", { error, origin });
   if (error instanceof Error) {
-    process.send &&
-      process.send({
-        type: "EVENT",
-        message: {
-          type: "UNCAUGHT_EXCEPTION",
-          payload: {
-            error: { name: error.name, message: error.message, stack: error.stack },
-            origin,
-          },
-          version: "v1",
+    safeSend({
+      type: "EVENT",
+      message: {
+        type: "UNCAUGHT_EXCEPTION",
+        payload: {
+          error: { name: error.name, message: error.message, stack: error.stack },
+          origin,
         },
-      });
+        version: "v1",
+      },
+    });
   } else {
-    process.send &&
-      process.send({
-        type: "EVENT",
-        message: {
-          type: "UNCAUGHT_EXCEPTION",
-          payload: {
-            error: {
-              name: "Error",
-              message: typeof error === "string" ? error : JSON.stringify(error),
-            },
-            origin,
+    safeSend({
+      type: "EVENT",
+      message: {
+        type: "UNCAUGHT_EXCEPTION",
+        payload: {
+          error: {
+            name: "Error",
+            message: typeof error === "string" ? error : JSON.stringify(error),
           },
-          version: "v1",
+          origin,
         },
-      });
+        version: "v1",
+      },
+    });
   }
 });
 

packages/cli-v3/src/entryPoints/managed-index-worker.ts

@@ -27,30 +27,39 @@ sourceMapSupport.install({
   hookRequire: false,
 });
 
+function safeSend(message: unknown) {
+  if (!process.connected || !process.send) {
+    return;
+  }
+  try {
+    process.send(message);
+  } catch {
+    // swallow: a throw here would re-enter this handler and busy-loop the worker
+  }
+}
+
 process.on("uncaughtException", function (error, origin) {
   if (error instanceof Error) {
-    process.send &&
-      process.send({
-        type: "UNCAUGHT_EXCEPTION",
-        payload: {
-          error: { name: error.name, message: error.message, stack: error.stack },
-          origin,
-        },
-        version: "v1",
-      });
+    safeSend({
+      type: "UNCAUGHT_EXCEPTION",
+      payload: {
+        error: { name: error.name, message: error.message, stack: error.stack },
+        origin,
+      },
+      version: "v1",
+    });
   } else {
-    process.send &&
-      process.send({
-        type: "UNCAUGHT_EXCEPTION",
-        payload: {
-          error: {
-            name: "Error",
-            message: typeof error === "string" ? error : JSON.stringify(error),
-          },
-          origin,
+    safeSend({
+      type: "UNCAUGHT_EXCEPTION",
+      payload: {
+        error: {
+          name: "Error",
+          message: typeof error === "string" ? error : JSON.stringify(error),
         },
-        version: "v1",
-      });
+        origin,
+      },
+      version: "v1",
+    });
   }
 });
 
@@ -191,7 +200,7 @@ await sendMessageInCatalog(
     importErrors,
   },
   async (msg) => {
-    process.send?.(msg);
+    safeSend(msg);
   }
 ).catch((err) => {
   if (err instanceof ZodSchemaParsedError) {
@@ -200,7 +209,7 @@ await sendMessageInCatalog(
       "TASKS_FAILED_TO_PARSE",
       { zodIssues: err.error.issues, tasks },
       async (msg) => {
-        process.send?.(msg);
+        safeSend(msg);
       }
     );
   } else {

packages/cli-v3/src/entryPoints/managed-run-worker.ts

@@ -77,37 +77,46 @@ sourceMapSupport.install({
   hookRequire: false,
 });
 
+function safeSend(message: unknown) {
+  if (!process.connected || !process.send) {
+    return;
+  }
+  try {
+    process.send(message);
+  } catch {
+    // swallow: a throw here would re-enter this handler and busy-loop the worker
+  }
+}
+
 process.on("uncaughtException", function (error, origin) {
   console.error("Uncaught exception", { error, origin });
   if (error instanceof Error) {
-    process.send &&
-      process.send({
-        type: "EVENT",
-        message: {
-          type: "UNCAUGHT_EXCEPTION",
-          payload: {
-            error: { name: error.name, message: error.message, stack: error.stack },
-            origin,
-          },
-          version: "v1",
+    safeSend({
+      type: "EVENT",
+      message: {
+        type: "UNCAUGHT_EXCEPTION",
+        payload: {
+          error: { name: error.name, message: error.message, stack: error.stack },
+          origin,
         },
-      });
+        version: "v1",
+      },
+    });
   } else {
-    process.send &&
-      process.send({
-        type: "EVENT",
-        message: {
-          type: "UNCAUGHT_EXCEPTION",
-          payload: {
-            error: {
-              name: "Error",
-              message: typeof error === "string" ? error : JSON.stringify(error),
-            },
-            origin,
+    safeSend({
+      type: "EVENT",
+      message: {
+        type: "UNCAUGHT_EXCEPTION",
+        payload: {
+          error: {
+            name: "Error",
+            message: typeof error === "string" ? error : JSON.stringify(error),
           },
-          version: "v1",
+          origin,
         },
-      });
+        version: "v1",
+      },
+    });
   }
 });
 

packages/core/src/v3/zodIpc.ts

@@ -143,6 +143,7 @@ interface ZodIpcConnectionOptions<
   process: {
     send?: (message: any) => any;
     on?: (event: "message", listener: (message: any) => void) => void;
+    connected?: boolean;
   };
   handlers?: ZodIpcMessageHandlers<TListenCatalog, TEmitCatalog>;
 }
@@ -257,7 +258,19 @@ export class ZodIpcConnection<
   }
 
   async #sendPacket(packet: Packet) {
-    await this.opts.process.send?.(packet);
+    // When the IPC channel is closed (e.g. parent process exited), there is no
+    // recipient — drop the packet rather than letting `process.send` throw
+    // ERR_IPC_CHANNEL_CLOSED, which would otherwise propagate as an
+    // uncaughtException and re-enter any handler that itself calls `process.send`.
+    if (this.opts.process.connected === false) {
+      return;
+    }
+
+    try {
+      await this.opts.process.send?.(packet);
+    } catch {
+      // swallow: channel raced from open to closed between the check and the send
+    }
   }
 
   async send<K extends GetSocketMessagesWithoutCallback<TEmitCatalog>>(