Extended configurations do not respect skipValidation

[oswaldoacauan]

I would expect that when extending a preset it would respect the skipValidation flag of where it was extended, instead it only follows the preset skipValidation configuration.

// packages/auth/env.ts
import { createEnv } from "@t3-oss/env-core";
export const env = () => createEnv({
  // no skipValidation set
});
 
// apps/web/env.ts
import { createEnv } from "@t3-oss/env-nextjs";
import { env as authEnv } from "@repo/auth/env";
 
export const env = createEnv({
  // ...
  extends: [authEnv()],
  skipValidation: !!process.env.SKIP_ENV_VALIDATION,
});

For the code above I would expect that if SKIP_ENV_VALIDATION=true all validations will be skipped, but thats not the case, the validations for /packages/auth/env.ts will still run.

To fix it, I need to replicate the skipValidation: !!process.env.SKIP_ENV_VALIDATION, on each of my presets.

Demo: https://codesandbox.io/p/devbox/7jhxrg

Is this the expected behaviour? It probably should be mentioned at least somewhere in the docs that presets are fully independent configurations and that they run in a standalone mode regardless of the options of where they were extended.