What are the potential pitfalls of using Composer to manage dependencies from non-Composer projects in PHP?

When using Composer to manage dependencies from non-Composer projects in PHP, potential pitfalls include compatibility issues, conflicts with existing dependencies, and difficulties in maintaining the external dependencies. To solve this, it is recommended to manually include the non-Composer dependencies in your project and manage them separately.

// Manually include non-Composer dependencies in your PHP project
require_once 'path/to/non-composer-dependency.php';