Failed to start debugger. Program could not be started.

[mkdirJava]

What version of Bun is running?

1.1.21

What platform is your computer?

Microsoft Windows NT 10.0.22631.0 x64

What steps can reproduce the bug?

Env Setup

Visual Studio Code ( Version: 1.92.0 )
Bun for Visual Studio Code Extension, Oven ( Version: v0.0.12, extension Id oven.bun-vscode)
Code found in
https://github.com/mkdirJava/BunIssueReplication

Steps

Clone the above repo
Open in Vscode
Whilst main panel has index.ts open run Vscode debug "Debug File"
Open "Debug Console" in the bottom panel ( might have to open a terminal and find the tab )
"Debug Console" reports
"Failed to start debugger.
Program must be a JavaScript or TypeScript file."

Looked further into the issue via logs found in
C:\Users<user>\AppData\Roaming\Code\logs\20240804T094251\window1\exthost\exthost.log

Looks like the extension is trying to open a reserved port

2024-08-04 09:46:15.465 [error] Error: listen EACCES: permission denied C:\Users<user>\AppData\Local\Temp\0vyubmzqvx4g.sock
at Server.setupListenHandle [as _listen2] (node:net:1881:21)

What is the expected behavior?

Given I have the repo cloned
https://github.com/mkdirJava/BunIssueReplication
And the Bun Extension installed
When I have the index.ts file open
And I have a break point set
And I click debug in Vscode
Then I should hit the debug line in debug mode

What do you see instead?

Failed to start debugger.
Program must be a JavaScript or TypeScript file.

Additional information

Looked further into the issue via logs found in
C:\Users<user>\AppData\Roaming\Code\logs\20240804T094251\window1\exthost\exthost.log

Looks like the extension is trying to open a reserved port

2024-08-04 09:46:15.465 [error] Error: listen EACCES: permission denied C:\Users<user>\AppData\Local\Temp\0vyubmzqvx4g.sock

[liudonghua123]

I got the similar logs in %appdata%\Code\logs\20240805T003523\window2\exthost\exthost.log

2024-08-05 00:37:56.722 [error] Error: listen EACCES: permission denied C:\Users\LIUD~1.H\AppData\Local\Temp\vd7f7p7ez1r.sock
    at Server.setupListenHandle [as _listen2] (node:net:1881:21)
    at listenInCluster (node:net:1946:12)
    at Server.listen (node:net:2061:5)
    at new UnixSignal (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\signal.ts:40:18)
    at DebugAdapter.#launch (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\adapter.ts:493:20)
    at DebugAdapter.launch (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\adapter.ts:439:18)
    at DebugAdapter.Adapter.request (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\adapter.ts:350:21)
    at DebugAdapter.emit (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\adapter.ts:297:26)
    at FileDebugSession.handleMessage (c:\Users\Liu.D.H\.vscode\extensions\oven.bun-vscode-0.0.12\src\features\debug.ts:195:20)
    at D.sendMessage (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:163:706)
    at s.$sendDAMessage (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:162:12040)
    at E.S (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:5980)
    at E.Q (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:5746)
    at E.M (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:4778)
    at E.L (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:3605)
    at i.value (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:2297)
    at n.B (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:83:737)
    at n.fire (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:83:954)
    at s.fire (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:97:14453)
    at i.value (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:177:8655)
    at n.B (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:83:737)
    at n.fire (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:83:954)
    at s.fire (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:97:14453)
    at MessagePortMain.<anonymous> (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:177:6781)
    at MessagePortMain.emit (node:events:519:28)
    at MessagePortMain.emit (node:domain:488:12)
    at Object.MessagePortMain._internalPort.emit (node:electron/js2c/utility_init:2:2285)

[mkdirJava]

I have done a little more "digging".
I've read through stackoverflow and these tickets.
The readings suggest to add in the location of the bun binary in the configuration

I still get this error in the logs

2024-08-04 17:57:39.466 [error] Error: listen EACCES: permission denied C:\Users\proje\AppData\Local\Temp\zkwvm6dkiif.sock
at Server.setupListenHandle [as _listen2] (node:net:1881:21)

however in the debug console I see

Failed to start inspector:
40 | }
41 | },
42 | close: () => {
43 | writer.close(), pendingMessages.length = 0;
44 | }
45 | }, parseUrl = function(input) {
^
TypeError: "ws+unix://C:\Users<user>\AppData\Local\Temp\fhyuenpoufo.sock?wait=1" cannot be parsed as a URL.
at internal:debugger:45:23
at new Debugger (internal:debugger:124:14)
at internal:debugger:100:13

So it looks like VsCode Bun extenstion is not recognizing it is working on a windows machine and is instead treating the windows path as a unix path

---

Then I used WSL2 (Ubuntu) and followed the same steps

1. In Vscode, open wsl2
2. Put a debugger on
3. Open Bun extenstion and update the location of the Bun binary
4. Use the same code and start a debugger
5. Run the debugger
6. IT WORKS !!!!

So I have a thought of:

The VSCode Bun Extension has an issue in Windows:

• Cannot treat certain file as sockets due to permissions

• The debug ws path is not sensitive to the windows platform

• There is an odd behavior to specify the location of the Bun binary . The extension mentions it will take bun from the path. I am unsure it does given the above findings

[liudonghua123]

I have also noticed some error logs in DEBUG CONSOLE. It's clear the error is related TypeError: "ws+unix://C:\Users\LIUD~1.H\AppData\Local\Temp\gi63g4zfvt4.sock?wait=1" cannot be parsed as a URL..

It's really strange, I only got Failed to start debugger\nProgram must be a JavaScript or Typescript file. a few days ago.

Failed to start inspector:
 40 |       }
41 |     },
42 |     close: () => {
43 |       writer.close(), pendingMessages.length = 0;
44 |     }
45 | }, parseUrl = function(input) {
                           ^
TypeError: "ws+unix://C:\Users\LIUD~1.H\AppData\Local\Temp\gi63g4zfvt4.sock?wait=1" cannot be parsed as a URL.
      at internal:debugger:45:23
      at new Debugger (internal:debugger:124:14)
      at internal:debugger:100:13

And the following error log in exthost.log.

2024-08-05 09:08:55.662 [error] Error: listen EACCES: permission denied C:\Users\LIUD~1.H\AppData\Local\Temp\x55hpvs12h.sock
    at Server.setupListenHandle [as _listen2] (node:net:1855:21)
    at listenInCluster (node:net:1920:12)
    at Server.listen (node:net:2019:5)
    at new UnixSignal (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\signal.ts:40:18)
    at DebugAdapter.#launch (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\adapter.ts:493:20)
    at DebugAdapter.launch (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\adapter.ts:439:18)
    at DebugAdapter.Adapter.request (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\adapter.ts:350:21)
    at DebugAdapter.emit (c:\Users\Liu.D.H\.vscode\extensions\bun-debug-adapter-protocol\src\debugger\adapter.ts:297:26)
    at FileDebugSession.handleMessage (c:\Users\Liu.D.H\.vscode\extensions\oven.bun-vscode-0.0.12\src\features\debug.ts:195:20)
    at D.sendMessage (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:163:706)
    at o.$sendDAMessage (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:162:12042)
    at S (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:5986)
    at S.Q (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:5752)
    at S.M (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:4778)
    at S.L (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:3605)
    at n.value (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:151:2297)
    at r.B (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:83:737)
    at r.fire (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:83:954)
    at o.fire (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:108:14502)
    at n.value (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:177:8639)
    at r.B (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:83:737)
    at r.fire (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:83:954)
    at o.fire (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:108:14502)
    at MessagePortMain.<anonymous> (c:\Users\Liu.D.H\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:177:6765)
    at MessagePortMain.emit (node:events:514:28)
    at MessagePortMain.emit (node:domain:488:12)
    at Object.MessagePortMain._internalPort.emit (node:electron/js2c/utility_init:2:2285)

From the error log and the code of vscode extension, it seems the following code doesn't working on windows.

bun/packages/bun-debug-adapter-protocol/src/debugger/adapter.ts

Lines 492 to 493 in 680f842

	const url = `ws+unix://${randomUnixPath()}`;
	const signal = new UnixSignal();

bun/src/js/internal/debugger.ts

Lines 55 to 56 in 680f842

	this.#url = parseUrl(url);
	this.#createBackend = (refEventLoop, receive) => {

I also evaluated new URL('ws+unix://C:\\Users\\LIUD~1.H\\AppData\\Local\\Temp\\2kic29xeo85.sock?wait=1') in Browser Devtools, node and bun. It seems only devtools parsed the js expression without errors.

And If I changed \\ to /, all of them parsed without errors.

[liudonghua123]

Well, after some debugging, I found the problem is related to unix option in Bun.serve on windows only support path that can not prefixed with a leading /. And the pathname of debug url parsed to the internal/debugger will auto prefixed with a leading /.

bun/src/js/internal/debugger.ts

Lines 266 to 269 in 680f842

	function parseUrl(input: string): URL {
	if (input.startsWith("ws://") || input.startsWith("ws+unix://") || input.startsWith("unix://")) {
	return new URL(input);
	}

bun/src/js/internal/debugger.ts

Lines 73 to 95 in 680f842

	#listen(): void {
	const { protocol, hostname, port, pathname } = this.#url;
	if (protocol === "ws:" || protocol === "ws+tcp:") {
	const server = Bun.serve({
	hostname,
	port,
	fetch: this.#fetch.bind(this),
	websocket: this.#websocket,
	});
	this.#url.hostname = server.hostname;
	this.#url.port = `${server.port}`;
	return;
	}
	if (protocol === "ws+unix:") {
	Bun.serve({
	unix: pathname,
	fetch: this.#fetch.bind(this),
	websocket: this.#websocket,
	});
	return;
	}

For the sample code.

import { pathToFileURL } from 'url';

Bun.serve({
  unix: 'D:/echo.sock', // works, pathToFileURL('D:/echo.sock').pathname or '/D:/echo.sock' failed with EUNKNOWN: An unknown error occurred
  fetch(req) {
    return new Response(`404!`);
  },
});

So the fix maybe update unix option in Bun.serve to support a optional leading prefix / on windows to keep compatible.

[mkdirJava]

raised a PR, but need to add in tests
#13099

[LeulAria]

getting this on mac aswell...

[RiskyMH]

This should be fixed by @snoglobe in #14048!