Custom-sandbox-command is executed in machine-root / instead of project/workspace root

[ELLIOTTCABLE]

Type: Bug

When creating a new VScode instance rooted at a particular folder, I expect a 'custom sandbox' command of the form opam exec $prog -- $args to function.

Unfortunately, it appears that the CWD is the machine root, /, instead of the project-root … so opam can't find binaries installed in the project-local switch.

Reproduction:

1. Create a local-sandbox in a new folder; install ocamllsp via opam
2. Use code . from that folder to lauch VScode
3. Attempt a custom-sandbox config like the following: pwd; opam exec $prog -- $args

For me, the logs demonstrate the following error:

external command (finished) {
  "shell": "pwd; opam exec ocamlc -- --version",
  "result": {
    "exitCode": 0,
    "stdout": "/\n4.13.1\n",
    "stderr": ""
  }
}

external command (finished) {
  "shell": "pwd; opam exec ocamllsp -- --version",
  "result": {
    "exitCode": 127,
    "stdout": "/\n",
    "stderr": "[ERROR] Command not found 'ocamllsp'\n"
  }
}

Extension version: 1.10.7
VS Code version: Code 1.71.0 (784b0177c56c607789f9638da7b6bf3230d47a8c, 2022-09-01T07:25:25.516Z)
OS version: Darwin arm64 21.6.0
Modes:
Sandboxed: No

System Info

Item	Value
CPUs	Apple M1 Pro (10 x 24)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_renderer: enabled_on video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: disabled_off
Load (avg)	3, 4, 7
Memory (System)	16.00GB (0.30GB free)
Process Argv	--crash-reporter-id ddb5da65-4654-412e-9dc3-738998ade011
Screen Reader	no
VM	0%

[sloane-shark]

This is also a problem for me, as my project tooling is specific to my project cwd, not installed globally on my system. A potential workaround would be to expose VS Code variables in the custom sandbox syntax so that one could do something like my_build_tool exec --cwd ${workspaceFolder} --command $prog -- $args

[jonahbeckford]

I very much would like to use the VS Code variables support. Specifically the following two:

• ${workspaceFolder}
• ${pathSeparator}