Capacitor plugin development: This dependency was not found

I am developing a Capacitor plugin (local) for personal use and followed these steps:

  1. Generated a plugin via npm init @capacitor/plugin [options] etc. (this worked fine)
  2. npm install --save …/pathtomyplugin (local path)
  3. npx cap sync

So far so good …
Package sits in the package.json (“capacitor-plugin-unlocks”: “file:…/capacitor-plugin-unlocks”,)
But when I try to build my ionic android project with:
ionic capacitor sync android / or ionic build

I get this:
This dependency was not found:

  • capacitor-plugin-unlocks in ./node_modules/cache-loader/dist/cjs.js??ref–12-0!./

My plugin is still in development and is not published on NPM.
How do I get this to work? (I am working within an ionic vuejs project)

I discovered that the folder in ./node-modules is only a link/shortcut to the other path … it does not actually copy the files over. I tried npm link as well but without success.
Manually copying the plugin into node modules does not help either

So far I discovered that it is a VueJS CLI specific error message.
I import the plugin as follows in my Vue project

import { UnlocksPlugin } from ‘capacitor-plugin-unlocks’;

If I remove this line it will build just fine.
Somehow the local capacitor plugin I created cannot be imported in my Vue project. Regardless is sitting in node_modules and my package.json

Looks like you skipped the workflow docs, or missed the line about running npm run build
That compiles the plugin code and creates the dist folder, which is what gets installed in your app.
Without it your app won’t find any plugin code or types.