difficulty with member routes - ruby-on-rails

Question

UPDATE: This was all a horrible mistake - I was updating the wrong routes file!
this does work: get 'users/:id/groups/' => 'users#groups'
I'd like to be able to see groups that belong to a specific user but I'm having trouble setting up a route that would resolve to:
/users/:id/groups
for some reason. I'm guessing devise is getting in the way, perhaps.
i've tried the following:
resources :users
match '/users/:id/groups', to: 'users#groups', via: :get
and
resources :users do
member do
get 'groups'
end
end
such a route never shows up when i call rake routes:
$ rake routes
Prefix Verb URI Pattern Controller#Action
groups GET /groups(.:format) groups#index
POST /groups(.:format) groups#create
new_group GET /groups/new(.:format) groups#new
edit_group GET /groups/:id/edit(.:format) groups#edit
group GET /groups/:id(.:format) groups#show
PATCH /groups/:id(.:format) groups#update
PUT /groups/:id(.:format) groups#update
DELETE /groups/:id(.:format) groups#destroy
calendar GET /calendar(/:year(/:month))(.:format) calendar#index {:year=>/\d{4}/, :month=>/\d{1,2}/}
root GET / calendar#index
new_user_session GET /users/sign_in(.:format) devise/sessions#new
user_session POST /users/sign_in(.:format) devise/sessions#create
destroy_user_session DELETE /users/sign_out(.:format) devise/sessions#destroy
user_password POST /users/password(.:format) devise/passwords#create
new_user_password GET /users/password/new(.:format) devise/passwords#new
edit_user_password GET /users/password/edit(.:format) devise/passwords#edit
PATCH /users/password(.:format) devise/passwords#update
PUT /users/password(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) registrations#cancel
user_registration POST /users(.:format) registrations#create
new_user_registration GET /users/sign_up(.:format) registrations#new
edit_user_registration GET /users/edit(.:format) registrations#edit
PATCH /users(.:format) registrations#update
PUT /users(.:format) registrations#update
DELETE /users(.:format) registrations#destroy
user_confirmation POST /users/confirmation(.:format) devise/confirmations#create
new_user_confirmation GET /users/confirmation/new(.:format) devise/confirmations#new
GET /users/confirmation(.:format) devise/confirmations#show
accept_user_invitation GET /users/invitation/accept(.:format) devise/invitations#edit
remove_user_invitation GET /users/invitation/remove(.:format) devise/invitations#destroy
user_invitation POST /users/invitation(.:format) devise/invitations#create
new_user_invitation GET /users/invitation/new(.:format) devise/invitations#new
PATCH /users/invitation(.:format) devise/invitations#update
PUT /users/invitation(.:format) devise/invitations#update
users GET /users(.:format) users#index
POST /users(.:format) users#create
new_user GET /users/new(.:format) users#new
edit_user GET /users/:id/edit(.:format) users#edit
user GET /users/:id(.:format) users#show
PATCH /users/:id(.:format) users#update
PUT /users/:id(.:format) users#update
DELETE /users/:id(.:format) users#destroy
events GET /events(.:format) events#index
POST /events(.:format) events#create
new_event GET /events/new(.:format) events#new
edit_event GET /events/:id/edit(.:format) events#edit
event GET /events/:id(.:format) events#show
PATCH /events/:id(.:format) events#update
PUT /events/:id(.:format) events#update
DELETE /events/:id(.:format) events#destroy

Answer 1

Why are you specifying member when you're trying to nest the resource? Did you try simply
resources :users do
resources :groups, only: :index
end