[Bug] Monaco Playground w/ Local Dev Environment Does Not Work

Start with the debugging and developing language support section of CONTRIBUTING.md and reproduce the build using the reported Windows, WSL, and Docker setups. Then inspect the failure path in monaco-editor-core/dev/vs/loader.js and the playground loading behavior. Done means the local project builds and the playground opens instead of loading indefinitely.

Reproducible in vscode.dev or in VS Code Desktop?

• Not reproducible in vscode.dev or VS Code Desktop

Reproducible in the monaco editor playground?

• Not reproducible in the monaco editor playground

Monaco Editor Playground Link

No response

Monaco Editor Playground Code

No response

Reproduction Steps

1. Follow the instructions at https://github.com/microsoft/monaco-editor/blob/main/CONTRIBUTING.md#debugging--developing-language-support
2. Start project
3. Get build errors

I have tried every possible combination of environments:

1. Using the workspace file on Windows and WSL
2. NOT using the workspace file on Windows and WSL
3. Using the Docker container

No matter what I do I can't get it to work.

Actual (Problematic) Behavior

I get the following build error:

Could not read source map for file://///home/runner/work/monaco-editor/monaco-editor/website/node_modules/%40react-aria/ssr/dist/module.js: UNC host 'home' access is not allowed
Could not read source map for file://///home/runner/work/monaco-editor/monaco-editor/website/node_modules/messagepack/dist/messagepack.es.js: UNC host 'home' access is not allowed
Could not read source map for file://///home/runner/work/monaco-editor/monaco-editor/website/node_modules/mobx-react/dist/mobxreact.esm.js: UNC host 'home' access is not allowed
Loading "monaco-editor-core" failed
loader.js:249
Error: [object Event]
    at Object.ensureError (C:\Users\Jackson\monaco-editor\node_modules\monaco-editor-core\dev\vs\loader.js:234:18)
    at ModuleManager._createLoadError (C:\Users\Jackson\monaco-editor\node_modules\monaco-editor-core\dev\vs\loader.js:1461:26)
    at ModuleManager._onLoadError (C:\Users\Jackson\monaco-editor\node_modules\monaco-editor-core\dev\vs\loader.js:1472:23)
    at loadNextPath (C:\Users\Jackson\monaco-editor\node_modules\monaco-editor-core\dev\vs\loader.js:1615:11)
    at Object.errorback (C:\Users\Jackson\monaco-editor\node_modules\monaco-editor-core\dev\vs\loader.js:1635:7)
    at OnlyOnceScriptLoader.triggerErrorback (C:\Users\Jackson\monaco-editor\node_modules\monaco-editor-core\dev\vs\loader.js:601:24)
    at C:\Users\Jackson\monaco-editor\node_modules\monaco-editor-core\dev\vs\loader.js:588:107
    at HTMLScriptElement.errorEventListener (https://microsoft.github.io/monaco-editor/node_modules/monaco-editor-core/dev/vs/loader.js:621:5) {phase: 'loading', moduleId: 'monaco-editor-core', neededBy: Array(1), stack: 'Error: [object Event]
    at Object.ensureErr…es/monaco-editor-core/dev/vs/loader.js:621:5)', message: '[object Event]'}

loader.js:250
Here are the modules that depend on it:
loader.js:251
(1) ['vs/language/json/monaco.contribution']

The playground does not work and loads forever:

Expected Behavior

The playground should open as expected.

Additional Context

This problem is nearly identical to https://github.com/microsoft/vscode/issues/175009