How to sourceMapPathOverrides

I am using docker to build a debug version of a wasm program, which makes the DWARF information contain file paths as used inside the docker container fs.

How can I use sourceMapPathOverrides to point to the right sources?

I have tried:

// in .vscode/launch.json
{
    "version": "0.2.0",
    "configurations": [
        "type": "node",
        "request": "launch",
        "name": "Debug Current Test File",
        "autoAttachChildProcesses": true,
        "skipFiles": ["<node_internals>/**", "**/node_modules/**"],
        "program": "${workspaceRoot}myproj/node_modules/vitest/vitest.mjs",
        "runtimeArgs": ["--preserve-symlinks"],
        "sourceMapPathOverrides": {
          "file:///workspace/*": "${workspaceFolder}/ccode/*",
        }
}

What does work is making a symlink /workspace -> ${workspaceFolder}/ccode

Basically I am looking for path substitutions like: https://developer.chrome.com/docs/devtools/wasm#map-path

Start with the .vscode/launch.json configuration and the sourceMapPathOverrides setting, then compare its behavior with the linked Chrome DevTools WebAssembly path-mapping documentation. Reproduce the Docker-built debug case and verify whether container paths such as file:///workspace/* resolve to local sources without the /workspace symlink.