See the full error here: http://notesapp.heroku.com/
I'm using DataMapper and dm-validations 0.10.2. No matter how much I tweak my models, I get the same error, or another one. Here's how my model looks like:
class User
include DataMapper::Resource
attr_accessor :password, :password_confirmation
property :id, Serial, :required => true
property :email, String, :required => true, :format => :email_address, :unique => true
property :hashed_password, String
property :salt, String, :required => true
property :created_at, DateTime, :default => Time.now
property :permission_level, Integer, :default => 1
validates_present :password_confirmation, :unless => Proc.new { |t| t.hashed_password }
validates_present :password, :unless => Proc.new { |t| t.hashed_password }
validates_is_confirmed :password
