new.internalInterface

Code example

<?php declare(strict_types = 1);

namespace Vendor {
	/** @internal */
	interface Handler {
		public function handle(): void;
	}
}

namespace App {
	$handler = new \Vendor\Handler(); // error: Instantiation of internal interface Vendor\Handler.
}

In practice, this is typically reported as Cannot instantiate interface (new.interface) because interfaces cannot be instantiated at all. The new.internalInterface identifier is reported when the internal access violation is the primary concern.

Why is it reported?

An internal interface is being used in an instantiation context from outside its root namespace. Interfaces marked as @internal are not meant to be used outside of the package or namespace where they are defined. They may change or be removed without notice in future versions.

How to fix it

Use a public (non-internal) type and a factory or concrete class from the package's public API instead:

 namespace App {
-	$handler = new \Vendor\Handler();
+	$handler = \Vendor\HandlerFactory::create();
 }

If you control the internal interface, consider making it public or providing a public alternative.