mixin.internalTrait

Code example

<?php declare(strict_types = 1);

namespace Vendor {
	/** @internal */
	trait InternalTrait {
		public function doSomething(): void {}
	}

	class Foo {
		use InternalTrait;
	}
}

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

Why is it reported?

The @mixin PHPDoc tag references a trait that is marked as @internal. Internal traits are not part of the public API of the package that defines them. Referencing internal types in PHPDoc tags creates a dependency on implementation details that may change without notice in future versions of the package.

Traits are not valid types in PHP, so using one in a @mixin tag is problematic regardless of the internal status.

How to fix it

Use a public class or interface provided by the package instead:

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

If no public alternative exists, remove the @mixin tag and implement the needed methods directly in the class.