Checklist

• This is not a Apple's bug.
• Reviewed the README and documents.
• Searched existing issues for ensure not duplicated.

Expected Behavior

We can compile example macOS application

Current Behavior

has compile error.

this let should be var

Steps to Reproduce

1. just run Example-macOS

Environments

• version: 0.4.0

• Swift version: 5.2.4

• Xcode version: 11.6