Hi!

I've opened a PR that adds full support for forcing mysqldump (or any custom dump binary) via the WP_CLI_MYSQLDUMP environment variable.

PR #6165 - Add robust support for WP_CLI_MYSQLDUMP override:
#6165

This update allows you to:

• Force /usr/bin/mysqldump even on MariaDB systems
• Override the dump client using either an absolute path or a plain command name
• Avoid failures when an invalid or non-executable path is provided
• Fall back safely to mariadb-dump or mysqldump when needed

Example usage:

WP_CLI_MYSQLDUMP=/usr/bin/mysqldump wp db export

This ensures wp db export always uses the correct binary on setups like yours.

Happy to improve the PR further if maintainers need anything!