[rollup-plugin-dynamic-import-variables] Unexpected token (3:7)

[FezVrasta]

I get the error in the title when I run yarn build with the below config:

// vite.config.js
import path from "path";
import { defineConfig } from "vite";
import { flowPlugin, esbuildFlowPlugin } from "@bunchtogether/vite-plugin-flow";

module.exports = defineConfig({
  optimizeDeps: {
    esbuildOptions: {
      plugins: [esbuildFlowPlugin()],
    },
  },
  plugins: [flowPlugin()],
  build: {
    lib: {
      entry: require.resolve("./lib/index.js"),
      name: "Popper",
      fileName: (format) => `popper-core.${format}.js`,
    },
  },
});

The code that throws is (lib/index.js):

/* eslint-disable import/no-unused-modules */
// @flow
export type * from './types';

export { position } from './position';
export { auto } from './modifiers/auto';
export { shift, limitShift } from './modifiers/shift';
export { flip } from './modifiers/flip';
export { arrow } from './modifiers/arrow';
export { offset } from './modifiers/offset';
export { hide } from './modifiers/hide';
export { size } from './modifiers/size';

export { default as rectToClientRect } from './utils/rectToClientRect';

This is my package.json:

{
  "name": "@popperjs/core",
  "version": "3.0.0-alpha.0",
  "scripts": {
    "dev": "vite",
    "build": "vite build",
    "serve": "vite preview"
  },
  "devDependencies": {
    "@bunchtogether/vite-plugin-flow": "^1.0.1",
    "flow-bin": "^0.165.0",
    "vite": "^2.6.4"
  }
}

I also have the same problem if I get rid of the build config and use the more basic config mode.

Ideas?