mysqldump Error 1045 Access denied despite correct passwords etc

Question

This is a tricky one, I have the following output:

mysqldump: Got error: 1045: Access denied for user \'root\'@\'localhost\' (using password: YES) when tr

Answer 1

Doing without the -u and -p worked for me (when I was logged in as root):

mysqldump --opt mydbname > mydbname.sql