Group membership error that has me pulling my hair out - ruby-on-rails-3

Question

I am getting this error:
2011-04-09T18:13:17+00:00 app[web.1]: NameError (uninitialized constant Group::Membership):
2011-04-09T18:13:17+00:00 app[web.1]: app/controllers/groups_controller.rb:25:in `show_members'
When I try and use the Show_members method in the groups controller. What have I done wrong?
user.rb
class User < ActiveRecord::Base
require 'paperclip'
# Include default devise modules. Others available are:
# :token_authenticatable, :confirmable, :lockable and :timeoutable
devise :database_authenticatable, :registerable, :confirmable,
:recoverable, :rememberable, :trackable, :validatable
has_and_belongs_to_many :roles
has_many :articles
has_many :ratings
has_many :rated_articles, :through => :ratings, :source => :articles
has_many :memberships, :dependent => :destroy
has_many :groups, :through => :memberships
...
membership.rb
class Membership < ActiveRecord::Base
attr_accessible :user_id, :group_id
belongs_to :user
belongs_to :group
validates_uniqueness_of :user_id, :message => "You can only join one group!"
end
group.rb
class Group < ActiveRecord::Base
require 'paperclip'
attr_accessible :name, :group_admin, :about, :location, :created_at, :avatar
validates_uniqueness_of :name, :group_admin
validates_length_of :name, :in => 4..40
has_many :memberships, :dependent => :destroy
has_many :users, :through => :memberships
end
group_controller
def show_members # members page
#group = Group.find(params[:id])
#members = #group.users <= THIS LINE IS THE ERROR
#group_admin = User.find(#group.group_admin)
respond_to do |format|
format.html
format.xml { render :xml => #group }
end
end
Update
def remove_user
#membership = Membership.find(params[:user_id, :group_id])
#membership.destroy
authorize! :remove_user, #membership
respond_to do |format|
format.html { redirect_to(:back, :notice => 'User was successfully Removed.') }
format.xml { head :ok }
end
I have this action in the groups_controller linked to in the show_members.html.erb
could the error be coming from this?

Answer 1

Oh my god. I just checked the git logs. Apparently, git decided not to add the memberships model file to the repo for some reason despite me doing git commit -a -m"blah". I thought the -a flag added everything?

Answer 2

I don't see an error in the code you pasted, but judging from the error code you get, you must be having a constant value somewhere that cannot be accessed. Do you have any Group.Membership call somewhere in your code ? (maybe a module?) Maybe you meant to write group.membership or something. I really can't spot anything else :/
EDIT :
Btw, i see something that should be causing a problem as well :
#group_admin = User.find(#group.group_admin)
group.admin is a name as a i see in your validations and you're looking up for an id. It should be find_by_group_admin in this one.