Code:
public class Test {
  public static void main(String[] args) {
    interface Foo {}
  }
}

An error message says:

"C:\Program Files\Java\jdk-15\bin\java.exe" Test.java
Test.java:3: error: interface not allowed here
    interface Foo {}
    ^
1 error
error: compilation failed

I would expect it to be like 'local interfaces are a preview feature
and are disabled by default'.

The same for local enums.