Vscode: VSCODE_PID not set on Linux, preventing debug-auto-attach from working

[maelvls]

Issue Type: Bug

I was investigating the Auto Attach feature not working on my Ubuntu box. I noticed that VSCODE_PID was used:

https://github.com/Microsoft/vscode/blob/bc24f98b5f70467bc689abf41cc5550ca637088e/extensions/debug-auto-launch/src/extension.ts#L120-L128

If I understand correctly, the extension.node-debug.startAutoAttach is created there:

https://github.com/Microsoft/vscode-node-debug/blob/dd8fca03672e05eca5d1e8e36f99c3a7f835459d/src/node/extension/autoAttach.ts#L57-L67

Thing is I don't think VSCODE_PID is set on Linux (not set in integrated terminal shells; in dev tools process.env.VSCODE_PID doesn't exist). The rootPid given is set by default to 0.

Sorry for not having investigating further. 🙄 I'll try to clone vscode and debug from there.

cc @weinand

VS Code version: Code 1.29.1 (bc24f98b5f70467bc689abf41cc5550ca637088e, 2018-11-15T19:07:43.495Z)
OS version: Linux x64 4.15.0-39-generic

System Info

|Item|Value|
|---|---|
|CPUs|Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz (4 x 3392)|
|GPU Status|2d_canvas: enabled
checker_imaging: disabled_off
flash_3d: enabled
flash_stage3d: enabled
flash_stage3d_baseline: enabled
gpu_compositing: enabled
multiple_raster_threads: enabled_on
native_gpu_memory_buffers: disabled_software
rasterization: disabled_software
video_decode: unavailable_software
video_encode: unavailable_software
webgl: enabled
webgl2: enabled|
|Load (avg)|1, 1, 1|
|Memory (System)|7.77GB (0.89GB free)|
|Process Argv|--proxy-server=localhost:3128 .|
|Screen Reader|no|
|VM|100%|

Extensions (27)

Extension|Author (truncated)|Version
---|---|---
project-manager|ale|9.1.0
insertnumbers|Asu|0.9.1
vscode-gpm|axe|1.0.0
solargraph|cas|0.17.6
npm-intellisense|chr|1.3.0
vscode-markdownlint|Dav|0.21.0
xml|Dot|2.3.2
EditorConfig|Edi|0.12.5
tslint|eg2|1.0.40
vscode-npm-script|eg2|0.3.5
prettier-vscode|esb|1.7.2
shell-format|fox|1.1.3
randomeverything|hel|0.0.3
Go|ms-|0.7.0
vscode-jest|Ort|2.9.2
vscode-docker|Pet|0.4.0
ruby|reb|0.20.0
java|red|0.34.0
rewrap|stk|1.9.1
shellcheck|tim|0.6.0
vscode-input-sequence|tom|0.2.0
vscode-java-debug|vsc|0.15.0
vscode-java-pack|vsc|0.4.0
vscode-java-test|vsc|0.10.0
vscode-maven|vsc|0.11.1
change-case|wma|1.0.0
markdown-all-in-one|yzh|1.7.0

[maelvls]

I reproduced the Auto-attach feature not working by running

• code --disable-extensions

• run example in https://github.com/Microsoft/vscode/issues/55918#issuecomment-411016230:

  • turn on auto-attach via the "Toggle Auto Attach" action
  • use a long-running node.js program "hello.js":
    var i = 0; setInterval(() => { console.log('hello world ' + i++); }, 1000);
  • set a breakpoint in line 3
  • open integrated terminal
  • enter node --inspect hello.js

  Debugger should hit breakpoint

But no breakpoint is hit 🤔

[weinand]

Auto attach works fine for me on Ubuntu 18.10:

What linux are you using?
Are you running tmux in your integrated terminal?

[maelvls]

I use /usr/bin/zsh as my default shell (chsh -s /usr/bin/zsh).

Running from vscode-1.29.1:

Is VSCODE_PID set in the integrated terminal on your side? Or is the debug-auto-attach extension working even though it is not set?

The only variable that is related to vscode (and allows me to detect I am inside the integrated terminal) is TERM_PROGRAM:

> env | grep -i vscode
TERM_PROGRAM=vscode

[weinand]

VS Code sets VSCODE_PID and that env var is inherited to the extension host where it is picked up by the node-debug or auto-attach extensions. It could be that the env var VSCODE_PID is removed before the integrated terminal is started. So that would explain why you are not seeing it.
In addition the auto attach code should work even if VSCODE_PID not found. In this case the processes tree starts at the process with the PID === 0 (which is more inefficient because the tree is larger).

[maelvls]

Got it! Thank you so much for the time spent on this issue by the way!!! ❤️

I also tested on 1.30.0-insider (c348be6) but same issue.

I'll try to switch back to plain bash with no fancy bashrc. 🙄

[weinand]

But does it make a difference if you use "plain bash"?

[maelvls]

I guess it shouldn't make a difference 😁
As I pretty much have no clue on what is preventing the auto-attach feature to work on my machine, I am trying every possibility 🙂

[weinand]

In VS Code could you please open the Chrome "Developer Tools" via the Windows menu.
Then switch to the "Console" tab .
In the REPL enter "process.env"
Expanding the array should show a "VSCODE_PID" variable.

[maelvls]

No sign of VSCODE_PID :disappointed:

[weinand]

Strange.

VSCODE_PID is set here:
https://github.com/Microsoft/vscode/blob/b36ee32fe7ca1da5285f1392be22c8bd14355315/src/vs/code/electron-main/main.ts#L161
and I do not see a reason why that piece of code is not executed in your version.

How are you running VS Code? An official build? Or are you building it yourself?

[maelvls]

I tried all vscode version I know of:

• from the official ppa using apt install code (1.29.1)
• from the official ppa using apt install code-insiders (1.30.0-insider)
• from source the OSS Dev version at 0d3a14402d88f0 using ./scripts/code-cli.sh

When trying the oss dev version of vscode, I couldn't find a way to debug the builtin extension ms-vscode.node-debug (in order to debug the logic behind auto-attach).

I tried ./scripts/code-cli.sh --builtin with 'local' (I cloned ms-vscode.node-debug and ran yarn inside). But I keep having issues (from vscode at 0d3a14402d88f0):

./scripts/code-cli.sh                         
[16:52:39] Syncronizing built-in extensions...
[16:52:39] You can manage built-in extensions with the --builtin flag
[16:52:39] [local] ms-vscode.node-debug: /home/mvalais/.vscode-oss-dev/vscode-node-debug ✔︎
[16:52:39] [marketplace] [email protected] ✔︎
[16:52:39] [disabled] ms-vscode.references-view
Debugger listening on ws://127.0.0.1:5874/ab468708-05f6-4855-b31a-6c63493cce5f
For help see https://nodejs.org/en/docs/inspector

It says

Activating extension 'ms-vscode.node-debug' failed: Cannot find module '/home/mvalais/.vscode-oss-dev/vscode-node-debug/dist/extension.js'.

The thing is vscode-node-debug does not contain any dist/ folder after yarn has been run (only a out/)

Anyway... :weary:

[weinand]

I wonder why we have no other reports of Auto Attach failing on linux...

I've even installed "zsh" but still I cannot reproduce the problem:

[weinand]

Interesting: when launching VS Code from the command line (instead of from the dock), I do not have the VSCODE_PID env var:

But Auto Attach still works!

[weinand]

Are you using a special version of the "/bin/ps" command?

Auto Attach relies on this command /bin/ps -ax -o pid,ppid,comm:20,command.
And the output should like this:

[maelvls]

I noticed the exact same thing about VSCODE_PID: when opened from the command-line, vscode won't have it; when opened from the (ubuntu) dock, it is set!

About /bin/ps, here is what it looks like when I launch a debug with break-right-now:

> /bin/ps --version
ps from procps-ng 3.3.12
> /bin/ps -ax -o pid,ppid,comm:20,command | grep 'node '
 10928   7978 node                 node --inspect-brk hello.js
 10944   5167 grep                 grep --color=auto --exclude-dir=.bzr --exclude-dir=CVS --exclude-dir=.git --exclude-dir=.hg --exclude-dir=.svn node

Here is a screencast of me trying to figure things out (I use the Peek app for Linux):

[flotwig]

I'm also experiencing this issue, process.env['VSCODE_PID'] is not set in my VS code and auto-attach doesn't work.

➜  ~ hostnamectl
        Machine ID: 1754e7222fb841289f9bb39e61a8e6cc
           Boot ID: 7c06867a3a5147a5958220e2ef09a5ac
  Operating System: Ubuntu 18.04.1 LTS
            Kernel: Linux 4.15.0-43-generic
      Architecture: x86-64
➜  ~ code --version
1.30.2
61122f88f0bf01e2ac16bdb9e1bc4571755f5bd8
x64

[robsonpeixoto]

The same on macOS

❯ code --version
1.35.1
c7d83e57cd18f18026a8162d042843bda1bcf21f
x64

❯ archey -o

Distro: OS X 10.14.5
Kernel: Darwin
Shell: /usr/local/bin/zsh
Terminal: screen vscode

[weinand]

We are currently working on a new version of the JavaScript (node.js) debug extension.
It will implement the "Auto attach" feature with a new approach not relying on VSCODE_PID.
Please give it a try.
For details see https://code.visualstudio.com/updates/v1_43#_new-javascript-debugger