Siteground reporting "no such file or directory" error

[kittenkamala]

Siteground has reported to the Hosting Team that they are encountering a "failed to open" error on their test runner. Slack conversation

The error is
wp-admin/css/view-transitions.min.css: Failed to open stream: No such file or directory

It may be related to phpunit-test-runner/issues/293 and https://core.trac.wordpress.org/ticket/64393

[stoyan0v]

We can close this bug, the recent test failures were caused by two main issues related to the build process and asset handling in the test environment:

1. Missing wp-admin Assets

WordPress recently introduced the View Transitions API, which requires assets located in wp-admin/css/. Our build script was previously only copying files from build/wp-includes/ to src/wp-includes/. This caused a fatal error ("Failed to open stream") because view-transitions.php could not find its required .min.css file in the src directory.

• Fix: Updated the build command to recursively copy build/wp-admin/* into src/wp-admin/.

2. Asset Minification Mismatch (SCRIPT_DEBUG)

After fixing the file paths, several tests failed because the environment was loading minified assets (e.g., comment-reply.min.js), while the PHPUnit test suite expected the non-minified source versions (e.g., comment-reply.js). By default, WordPress core tests expect uncompressed scripts.

• Fix: Modified prepare.php to inject define( 'SCRIPT_DEBUG', true ); into the test configuration. This forces WordPress to use the source assets, aligning the environment with the test suite's expectations.

Result: These changes resolved the 100+ fatal errors and the subsequent functional test failures. All tests are now passing (green).