What Could be the Issue with Integrating a Custom Executor for the 'serve' Operation?

Question

I aim to incorporate my custom executor into the serve operation.

Therefore, I've designed an executor blueprint, with the main function structured as follows:

import { ServeExecutorSchema } from './schema';
import { externalSchematic } from '@angular-devkit/schematics';

export default async function runExecutor(options: ServeExecutorSchema) {
  // Implement custom functionality here..
  // The remainder remains unchanged.
  return externalSchematic('@angular-devkit/build-angular', 'dev-server', {
    ...options,
  });
  // console.log('Executor ran for Serve', options);
  // return {
  //   success: true,
  // };
}

In the project.json/angular.json file:

"serve": {
      "executor": "@app/angular:serve",
      "configurations": {...}

Executing the schematics with: nx serve app.

Encountered:

yarn nx serve app
yarn run v1.22.19
$ app/node_modules/.bin/nx serve app

> nx run app:serve:development
 ——————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————

 >  NX   Running target serve for project app failed

   Failed tasks:

   - app:serve:development

   Hint: run the command with --verbose for more details.

error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

What could be the issue here?