.env vars empty in .env.development

[pinggi]

Describe the bug

The environmental variables defined in .env file cannot be used in .env.development and .env.production files.

Steps to reproduce

1. define .env variable:

PORT=4000

2. define .env.development variable:

REACT_APP_URL=http://localhost:${PORT}

3. Add code showing the value

console.log(process.env.REACT_APP_URL);

4. Run the app and see the value

The result is: "http://localhost:" - the port is missing.

If the port is defined in the same file .env.development:

PORT=4000
REACT_APP_URL=http://localhost:${PORT}

Then the result is correct: "http://localhost:4000".