Wordpress function cache_users not found after update to 6.1

Question

I am getting error while running a function get_users() in my custom plugin

PHP Fatal error: Uncaught Error: Call to undefined function cache_users() in /Users/priyankgohil/sites/upw-new/wp-includes/class-wp-user-query.php:843

Stack trace: #0 /Users/priyankgohil/sites/upw-new/wp-includes/class-wp-user-query.php(79): WP_User_Query->query() #1 /Users/priyankgohil/sites/upw-new/wp-includes/user.php(763): WP_User_Query->__construct(Array) #2 /Users/priyankgohil/sites/upw-new/wp-content/plugins/my-plugin/Inc/BaseController.php(214): get_users(Array)

is anyone have solution or facing same issue after upgrade to wordpress 6.1

Answer 1

To include the fix in your own plugin code, try this (worked for me)

add_action('pre_get_users','fix_cache_users_bug');

function fix_cache_users_bug($query) {
    if ( ! function_exists( 'cache_users' ) ) {
        require_once ABSPATH . WPINC . '/pluggable.php';
    }   
}

I'd suggests that's better than hacking core files.

Answer 2

I solved this problem in the following way:

1. Download latest wordpress file from https://wordpress.org/download/
2. Zip all files & folders except wp-content folder and wp-config.php file
3. upload zipped file created at step 2 to root directory of site
4. Unzip and replace all files and folders

I made a video on Youtube hope it can help: https://www.youtube.com/watch?v=uTs0WBOOMew

Answer 3

Until this gets fixed, you can add the following above line 843 of wp-includes/class-wp-user-query.php:

if ( ! function_exists( 'cache_users' ) ) {
    require_once ABSPATH . WPINC . '/pluggable.php';
}

This function looks like it was introduced in the new version, and the code (in other areas) appears to check for functions within pluggable.php before requiring the file.

Answer 4

It can be patched from a must-use plugin. Add a new file at /wp-content/mu-plugins/cache-users.php and add this to it:

<?php
/**
 * cache_users() Polyfill
 *
 * Patch for issues with WP_User_Query in WP 6.1
 */
if ( ! function_exists( 'cache_users' ) ) {
  function cache_users( $results ) {
    return $results;
  }
}

That will safely patch the issue without modifying the WordPress core files until it's resolved in a follow-up release. It's bypassing the cache which isn't ideal, but it resolves any fatal errors reliably.