WP-CLI Error: PHP Deprecated: implode(): Passing glue string after array is deprecated.

I use WP-CLI to maintain my WordPress sites. It’s simple, it handy, and it works without any issues.

For example, I can updates all my plugins and themes (if updates are available) by executing wp theme update --all and wp plugin update --all. If WordPress core engine is available, I only need to run wp core update.

But there is a problem when I update WordPress plugins recently. Running wp plugin update --all to update all available plugin updates give me an error:

PHP Notice:  Trying to access array offset on value of type null in phar:///usr/local/bin/wp/vendor/wp-cli/extension-command/src/Plugin_Command.php on line 663
Notice: Trying to access array offset on value of type null in phar:///usr/local/bin/wp/vendor/wp-cli/extension-command/src/Plugin_Command.php on line 663

But, all updatable plugins were updated successfully. I tried to find the solutions, but I found nothing. I also try to use the nightly version via wp update --nightly, but still no luck.

Here are my wp --info

OS: Linux 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64
Shell: /bin/bash
PHP binary: /usr/bin/php7.4
PHP version: 7.4.3
php.ini used: /etc/php/7.4/cli/php.ini
MySQL binary: /usr/bin/mysql
MySQL version: mysql Ver 8.0.21-0ubuntu0.20.04.4 for Linux on x86_64 ((Ubuntu))
SQL modes:
WP-CLI root dir: phar://wp-cli.phar/vendor/wp-cli/wp-cli
WP-CLI vendor dir: phar://wp-cli.phar/vendor
WP_CLI phar path: /home/path/to/my/directory/
WP-CLI packages dir:
WP-CLI global config:
WP-CLI project config:
WP-CLI version: 2.5.0-alpha-068c252