Question: How can local dependencies be referenced in pxt.json

Hello,

When developing my micro:bit v2 application using TypeScript, I forked an external dependency on GitHub to make a few changes that I want to propose as a Pull Request.

Now I need to link that local dependency to my application to test my changes.

In the pxt.json, dependencies are defined in this fashion:

{
    "dependencies": {
        "core": "*",
        "sonarbit": "github:elecfreaks/pxt-sonarbit#v1.0.9"
    }
}

I tried to change the above to:

{
    "dependencies": {
        "core": "*",
        "sonarbit": "local:../pxt-sonarbit"
    }
}

However, when running mkc build, I got

Exception: Error: Error: extension sonarbit is missing pxt.json

The pxt.json file is there. Even when changing the relative path to an absolute path, the same happened.

I know it's possible to achieve what I'm after in the online MakeCode editor. Is the same possible locally when using mkc?
The online editor is so inconvenient for day-to-day development.

Start with the application pxt.json and the mkc build command, reproducing the failure with the local:../pxt-sonarbit dependency and checking the referenced dependency's pxt.json. Done means the local fork can be referenced and built successfully with mkc, or the supported limitation and workflow are documented.