Logger interface incompatible with Psr\Log\LoggerTrait:log() (968)

[areklam]

Describe the Bug

The WooCommerce logging interface module attempt to use Psr\Log\LoggerTrait with invalid interface. The classes WooCommerceLogger and NullLogger both implement Psr\Log\LoggerInterface and declare the log function without a function return type.

The solution is to include the return type for the log functions which is supposed to be void.

To Reproduce

1. Install and activate plugin
2. See error

Screenshots

Expected Behavior

Plugin activated, no errors.

Actual Behavior

Error message
Fatal error: Declaration of WooCommerce\WooCommerce\Logging\Logger\WooCommerceLogger::log($level, $message, array $context = []) must be compatible with Psr\Log\LoggerTrait::log($level, Stringable|string $message, array $context = []): void

Environment

• WordPress Version 6.2.2
• WooCommerce Version 7.9.0
• Plugin Version 2.2.0
• Roots Bedrock

[InpsydeNiklas]

Hi @areklam, thanks for the issue & PR.
However, psr/log version 3.0.0 supports only php >=8.0.0 and the declaration of arguments are using “Union types”, as seen here. PayPal Payments supports PHP 7.2, so it cannot be made compatible with this at this time. This means the primary suggestion would be to downgrade this library in your theme, while the development team is investigating other ways to improve the compatibility with third-party plugins/themes that use a newer psr/log version.

[williarin]

Hi, using Sword (Bedrock-like for Symfony) this error makes it impossible to use this plugin as well.
Maybe it's too late at this stage of development, but an option would be to prefix namespaces with https://github.com/typisttech/imposter-plugin so there's no conflict to external plugins or apps.

[robindarlington]

For what it's worth to anyone dealing with this issue in 2025. Here is the simple 1 line fix (hack) I have been using for the last several versions:

Replace

`public function log( $level, $message, array $context = array() ) `

with

`public function log($level, string|\Stringable $message, array $context = []): void`

In /woocommerce-paypal-payments/modules/woocommerce-logging/src/Logger/WooCommerceLogger.php on line 58.

Might it be possible to include this change in an upcoming release ?

[InpsydeNiklas]

We appreciate your suggestions and patience. Due to union types, adopting this change in the core plugin would require raising the minimum PHP version to 8.0. Since our minimum PHP requirement was only recently increased to 7.4, we’re not yet able to introduce union types in the plugin.

However, we created a fix for an upcoming major update (date TBD) using scoped psr namespaces to address the compatibility issue. In the meantime, we have prepared an alpha version using this solution which you can download from here.
We would appreciate your feedback on whether this alpha version resolves the fatal errors you’ve been encountering with the regular plugin. Thank you!