Server build:.env not loaded with Nitro + TanStack Start

I’m using TanStack Start + Nitro, but after building the app my server‑side code can no longer see the variables defined in .env. It seems like Nitro isn’t loading the .env file on build — any idea what I’m missing or how to make it load correctly?

My Vite Config

const config = defineConfig(({ mode }) => {
  console.log('VITE_DEPLOY_TARGET:', mode);
  const useNitro = mode === 'nitro';

  console.log('Using deploy target:', useNitro ? 'Nitro' : 'Netlify');

  return {
    plugins: [
      devtools(),
      viteTsConfigPaths({
        projects: ['./tsconfig.json'],
      }),
      tailwindcss(),
      tanstackStart(),
      useNitro ? nitro() : netlify(),
      viteReact(),
    ],
    nitro: useNitro ? {} : undefined,
  };
});

const config = defineConfig(({ mode }) => {
  console.log('VITE_DEPLOY_TARGET:', mode);
  const useNitro = mode === 'nitro';

  console.log('Using deploy target:', useNitro ? 'Nitro' : 'Netlify');

  return {
    plugins: [
      devtools(),
      viteTsConfigPaths({
        projects: ['./tsconfig.json'],
      }),
      tailwindcss(),
      tanstackStart(),
      useNitro ? nitro() : netlify(),
      viteReact(),
    ],
    nitro: useNitro ? {} : undefined,
  };
});

const config = defineConfig(({ mode }) => {
  console.log('VITE_DEPLOY_TARGET:', mode);
  const useNitro = mode === 'nitro';

  console.log('Using deploy target:', useNitro ? 'Nitro' : 'Netlify');

  return {
    plugins: [
      devtools(),
      viteTsConfigPaths({
        projects: ['./tsconfig.json'],
      }),
      tailwindcss(),
      tanstackStart(),
      useNitro ? nitro() : netlify(),
      viteReact(),
    ],
    nitro: useNitro ? {} : undefined,
  };
});

const config = defineConfig(({ mode }) => {
  console.log('VITE_DEPLOY_TARGET:', mode);
  const useNitro = mode === 'nitro';

  console.log('Using deploy target:', useNitro ? 'Nitro' : 'Netlify');

  return {
    plugins: [
      devtools(),
      viteTsConfigPaths({
        projects: ['./tsconfig.json'],
      }),
      tailwindcss(),
      tanstackStart(),
      useNitro ? nitro() : netlify(),
      viteReact(),
    ],
    nitro: useNitro ? {} : undefined,
  };
});