NODE_ENV is not accessible in vue.config.js

[sanchitnevgi]

Version

3.0.0-beta.6

Reproduction link

https://github.com/sanchitgn/chunk/blob/master/vue.config.js#L1

Steps to reproduce

1. Create new project (vue create)
2. Add vue.config.js
3. Log process.env.NODE_ENV in vue.config.js

What is expected?

The environment (development/production) should be output

What is actually happening?

The output is undefined

---

To modify webpack configuration (plugins, loaders, etc), it is necessary to know the node environment

[LinusBorg]

Duplicate of #959