From 2ac9a8ce9797f62f8278ed5175fed5764c45bc93 Mon Sep 17 00:00:00 2001
From: Aaron Munger <aamunger@microsoft.com>
Date: Thu, 4 Apr 2024 08:48:19 -0700
Subject: [PATCH] log errors that occur in bg threads

---
 src/standalone/api/kernels/backgroundExecution.ts | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/standalone/api/kernels/backgroundExecution.ts b/src/standalone/api/kernels/backgroundExecution.ts
index 97b9a6cae18..bf0b12757c2 100644
--- a/src/standalone/api/kernels/backgroundExecution.ts
+++ b/src/standalone/api/kernels/backgroundExecution.ts
@@ -22,12 +22,14 @@ export async function execCodeInBackgroundThread<T>(
     const api = createKernelApiForExtension(JVSC_EXTENSION_ID, kernel, { accessAllowed: true });
     const mime = `application/vnd.vscode.bg.execution.${counter}`;
     const mimeFinalResult = `application/vnd.vscode.bg.execution.${counter}.result`;
+    const mimeErrorResult = `application/vnd.vscode.bg.execution.${counter}.error`;
     let displayId = '';
 
     const codeToSend = `
 def __jupyter_exec_background__():
     from IPython.display import display
     from threading import Thread
+    from traceback import format_exc
 
     # First send a dummy response to get the display id.
     # Later we'll send the real response with the actual data.
@@ -41,8 +43,8 @@ def __jupyter_exec_background__():
     def bg_main():
         try:
             output.update({"${mimeFinalResult}": do_implementation()}, raw=True)
-        except:
-            pass
+        except Exception as e:
+            output.update({"${mimeErrorResult}": format_exc()}, raw=True)
 
 
     Thread(target=bg_main, daemon=True).start()
@@ -85,6 +87,11 @@ del __jupyter_exec_background__
         if (token.isCancellationRequested) {
             return;
         }
+        const error = output.items.find((item) => item.mime === mimeErrorResult);
+        if (error) {
+            traceWarning('Error in background execution:\n', new TextDecoder().decode(error.data));
+            return;
+        }
         const metadata = getNotebookCellOutputMetadata(output);
         if (!metadata?.transient?.display_id) {
             continue;