importing gulpfile.babel.js into another gulpfile.babel.js throws ES6 error

I am trying to run a parent folder (global) gulpfile.babel.js within a sub folder gulpfile.babel.js and have run in to an error:

```
export default function(gulp, config) {
^^^^^^

SyntaxError: Unexpected token 'export'
```

Code is:

```
// parent gulpfile.babel.js
export default function(gulp, config) {
return gulp;
}
```

```
// child gulpfile.babel.js
import {config} from './gulp.config.js';
import gulp from 'gulp';
import globalTask from '../gulpfile.babel.js';
globalTask(gulp, config);

// project-specific tasks using gulp and config goes here

export const setup = (done) => {
console.log(`Activity tasks for ${config.name}`);
done();
}

export default setup;
```
```
// package.json (in parent)
{
"name": "activity-base",
"version": "0.0.1",
"description": "Activity base.",
"scripts": {
"start": "gulp",
"prod": "gulp build --prod"
},
"author": "Neb",
"license": "ISC",
"devDependencies": {
"@babel/core": "^7.9.6",
"@babel/preset-env": "^7.9.6",
"@babel/register": "^7.9.0",
"babel-loader": "^8.1.0",
"del": "^5.1.0",
"gulp": "^4.0.2",
"gulp-if": "^3.0.0",
"webpack": "^4.43.0",
"webpack-stream": "^5.2.1",
"yargs": "^15.3.1"
},
"dependencies": {},
"babel": {
"presets": [
"@babel/preset-env"
]
}
}
```

If I change the parent gulpfile.babel.js to ES5 code it runs fine:

```
// parent gulpfile.babel.js
module.exports = function(gulp, config) {
// project-independent stuff using gulp and config goes here
console.log(`Do project-wide tasks for the ${config.name}`);
return gulp;
};
```

Any ideas what's going on and how to fix?

Thanks in advance :)

Start by comparing the parent and child gulpfile.babel.js files and the Babel configuration in package.json, then reproduce the import through the documented gulp entry point. Trace why the parent file is not transformed when imported and verify that the parent and child gulpfiles can work together without the Unexpected token 'export' error.

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