Redmine

I installed Redmine using Bitnami Redmine Stack 2.3.3-0. Redmine is working fine. Below is the information fetch from the installed Redmine:

Information

Redmine 2.3.3.stable

Default administrator account changed True
Attachments directory writable True
Plugin assets directory writable True
RMagick available (optional) True

Environment:
Redmine version 2.3.3.stable
Ruby version 1.9.3-p231 (2012-05-25) [i386-mingw32]
Rails version 3.2.13
Environment production
Database adapter Mysql2
Redmine plugins:
no plugin installed

Now, I've set the mysql root account access with no password. I can confirm that it is accessible via terminal by 'mysql -u root' and phpmyadmin with just username 'root'.

Mantis is install in the same database with different schema name 'bugtracker' (Redmine is redmine), and I can access Mantis (version 1.2.15) with the settings below taken from config_inc.php below:

$g_hostname = 'localhost';
    $g_db_type = 'mysql';
    $g_database_name = 'bugtracker';
    $g_db_username = 'root';
    $g_db_password = '';

*When I do rake redmine:migrate_from_mantis RAILS_ENV=production

C:\BitNami\redmine-2.3.3-0\apps\redmine\htdocs>rake redmine:migrate_from_mantis
RAILS_ENV=production

WARNING: Your Redmine data will be deleted during this process.
Are you sure you want to continue ? [y/N] y

Please enter settings for your Mantis database
adapter [mysql2]:
host [localhost]:
database [bugtracker]:
username [root]:
password []:
encoding [UTF-8]:

Migrating usersrake aborted!
Validation failed: Password is too short (minimum is 8 characters)

Tasks: TOP => redmine:migrate_from_mantis
(See full trace by running task with --trace)

C:\BitNami\redmine-2.3.3-0\apps\redmine\htdocs>*

What is that about? No password is password too short? How am I going to connect to Mantis database? I even tried setting different users with all grants and long passwords, I'm highly in doubt there's a problem with the script. See attachments for more info. Thank you.

P/S: What is this 'admin' and password 'mantis' setting about? # Users
print "Migrating users"
User.delete_all "login <> 'admin'"
users_map = {}
users_migrated = 0
MantisUser.all.each do |user|
u = User.new :firstname => encode(user.firstname),
:lastname => encode(user.lastname),
:mail => user.email,
:last_login_on => user.last_visit
u.login = user.username
u.password = 'mantis'