I installed MySql 3.23.52 on OS X (using the build from entropy.ch).
The installation goes through without any problem, I can start the DB. But when I want to change the password using
./bin/mysqladmin -u root password 'new-password' OR
./bin/mysqladmin -u root -h myimac.local. password 'new-password'

it fails, telling me that localhost is not authorised to change the password...any clue?