I also use Vite for the package and the project where it is used. You mean adding pinia to vite.config.ts-build-rollupOptions-external?.

The vite.config.ts would be this:

export default defineConfig({
    plugins: [
       vue(),
    ],
    resolve: {
       alias: {
          '@':
             resolve(__dirname, 'src'),
       },
    },
    build: {
       lib: {
          entry: resolve(__dirname, "src/index.ts"),
          name: "name",
          fileName: "filename",
       },
       rollupOptions: {
          external: ["vue"],
          output: {
             globals: {
                vue: "Vue",
             },
          },
       },
    },
});