Once again, another one of those posts for my future self!
If you’re getting:
Client does not support authentication protocol requested by server; consider upgrading MySQL client
…after upgrading to MySQL 4.1+, it’s because your client application doesn’t support the new password hashes.
The solution is to do the following:
SET PASSWORD FOR ‘theuser’@'thehost’ = OLD_PASSWORD(‘thepassword’);
For a more permanent solution [...]