I’ve upgraded to babel-plugin-transform-imports v2 and got some errors like:

imports.js?ce64:168 Uncaught Error: Unknown import from Quasar: function Vue (options) {

Reason: https://www.npmjs.com/package/babel-plugin-transform-imports#version-20-breaking-changes

Solution: Slightly changed babel config:

module.exports = {
  "presets": [
    "@vue/app"
  ],
  "plugins": [
    [
      "transform-imports",
      {
        "quasar": {
          "transform": require('quasar/dist/babel-transforms/imports.js'),
          "preventFullImport": true
        }
      }
    ]
  ]
}

Notice the require(). Hope this helps anyone