[PHP 8] Error: Callable ["\\RankMath\\CLI\\Commands","sitemap_generate"] does not exist, and cannot be registered as `wp rankmath sitemap generate`.

[josenobile]

It fails with a PHP fatal error when calling from wp-cli Callable ["\\RankMath\\CLI\\Commands","sitemap_generate"] does not exist, and cannot be registered aswp rankmath sitemap generate.

To Reproduce Steps to reproduce the behavior:

1. Install wp-cli: curl https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar -s --output /usr/local/bin/wp && chmod +x /usr/local/bin/wp
2. Execute any wp-cli command (as no root), using PHP 8.0.1, for example: wp cron event run --due-now --path=/home/user/whereWordpressIsInstalled

Expected behavior The command runs with an exit code = 0 and an output similar to what in PHP 7.4.14 is gotten:

Executed the cron event 'action_scheduler_run_queue' in 0.006s.
Success: Executed a total of 1 cron event.

Additional context WP-CLI 2.4.0 WordPress version: 5.6 PHP 8.0.1 (cli) (built: Jan 8 2021 10:09:55) ( NTS gcc x86_64 ) mysql Ver 15.1 Distrib 10.3.27-MariaDB, for Linux (x86_64) using readline 5.1 Linux ... 4.18.0-147.8.1.el7h.lve.1.x86_64 #1 SMP Mon Jun 29 09:05:02 EDT 2020 x86_64 x86_64 x86_64 GNU/Linux Database revision: 49752 TinyMCE version: 4.9110 (49110-20201110) Package language: es_ES

[balazsrm]

Hi @josenobile

Thank you for reporting this issue. We have found what's causing it, and the fix for it will be included in the next update for Rank Math.

The issue is happening because there was a breaking change in PHP 8:

Removed ability to call non-static methods statically. Thus is_callable will fail when checking for a non-static method with a classname (must check with an object instance).

For future reference, to fix this issue all you need to change is one line: https://github.com/rankmath/seo-by-rank-math/blob/cd0df1fae4c474dc9954a82799a5b5a6e631baed/includes/cli/class-commands.php#L31

Just need to add the static keyword: public static function sitemap_generate( $args ) {

After doing this, WP-CLI should work correctly. Hope that helps.