I followed the guide from
https://docs.webstudio.is/contributing/contributing-for-developers, and it works, but the loading is very slow even though it runs on localhost.
I tried running pnpm build and pnpm start in the apps/builder directory after slightly modifying the vite.config.js file by removing the Vercel plugin. (Without removing it, pnpm start wouldn't work—probably because I don't know how to run it locally with the Vercel plugin.) This approach works, but the login options (GitHub and secret) are disabled, even though I've configured them in .env, .env.production, and .env.development.
The .env file works when running pnpm dev but not with pnpm start.