Mybb.rb imports nothing

Product Support Migration
12

What would you recommend in this case?

loading existing groups...
loading existing users...
loading existing categories...
loading existing posts...
loading existing topics...
/usr/local/lib/ruby/gems/2.3.0/gems/mysql2-0.4.8/lib/mysql2/client.rb:89:in `connect': Access denied for user 'root'@'localhost' (using password: NO) (Mysql2::Error)
        from /usr/local/lib/ruby/gems/2.3.0/gems/mysql2-0.4.8/lib/mysql2/client.rb:89:in `initialize'
        from mybb.rb:31:in `new'
        from mybb.rb:31:in `initialize'
        from mybb.rb:304:in `new'
        from mybb.rb:304:in `<main>'