mixin.internalEnum

Code example

<?php declare(strict_types = 1);

namespace Vendor {
	/** @internal */
	enum InternalEnum {
		case A;
	}
}

namespace App {
	/** @mixin \Vendor\InternalEnum */
	class MyClass {}
}

Why is it reported?

A @mixin PHPDoc tag references an enum that is marked as @internal. Internal types are not meant to be used outside of the package or namespace where they are defined. Depending on internal types in @mixin tags creates a fragile dependency on implementation details that can change without notice.

How to fix it

Use a public (non-internal) type in the @mixin tag instead:

 namespace App {
-	/** @mixin \Vendor\InternalEnum */
+	/** @mixin \Vendor\PublicClass */
 	class MyClass {}
 }

If the library provides a public alternative, use that. Otherwise, define your own type or remove the @mixin tag and implement the needed methods directly.