Problem is that GoDaddy uses not only CNAME, but A (host) records too. While CNAME is easy to configure (you just add your bitbucket.org record to the www line of the list, right?) — A (host) requires the record to appear as IP. Bitbucket doesn't provide any IP. When I try to configure Bitbucket side, I get an error, that the domain is pointing to [IP of the A-record].