Site Health: Avoid shell error output when Ghostscript is missing.

[accolette]

When Ghostscript (gs) is not installed, WP_Debug_Data::get_wp_media() runs gs --version through exec(). exec() only captures stdout, so the shell prints an error on stderr (for example sh: 1: gs: not found, the exact wording depends on the shell). It is visible in the terminal, in WP-CLI and in PHPUnit output.

The "Ghostscript version" field is already correctly reported as "Not available", so this change only removes the unwanted shell output. The reported result does not change.

Changes

• Check that gs exists with command -v before running gs --version.
• Add tests/phpunit/tests/admin/wpDebugData.php with two tests on the Ghostscript field returned by WP_Debug_Data::debug_data():
  • gs is available (a fake gs script is added to the PATH): the version is reported.
  • gs is missing (the PATH does not contain it): the field is reported as "not available".

Testing

Run:

npm run test:php -- --filter Tests_Admin_wpDebugData

• Without the fix: the 2 tests pass, and sh: 1: gs: not found is printed in the output.
• With the fix: the 2 tests pass, and nothing is printed.

The tests cannot assert on the message itself, because it is written to stderr by the child process and not by PHP. They check that the reported value is unchanged, and the message is checked by looking at the output. WP-CLI steps to reproduce are in the ticket.

Trac ticket: https://core.trac.wordpress.org/ticket/66245

Use of AI Tools

AI assistance: Yes. Tool(s): Claude (Anthropic). Used for: helping me understand the problem, looking up the affected version, suggesting reproduction commands, and drafting the PHPUnit tests, the Trac ticket text and this description. I found the bug, reproduced it, ran the tests and tested the patch.

The fix was suggested by Chouby.

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[github-actions]

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