Deploying to Rails project to Heroku: Could not find activemodel - ruby-on-rails-3

Question

I am relatively new to rails and have been working my way through the Michael Hartl Tutorial. Throughout I have been deploying my projects to Heroku, however now I am at the end of chapter 5, I am getting an "application error". Specifically I am getting the following errors when I look into my Heroku logs:
2012-01-04T03:05:04+00:00 app[web.1]: Could not find activemodel-3.2.0.rc1 in any of the sources
2012-01-04T03:05:06+00:00 heroku[web.1]: State changed from starting to crashed
2012-01-04T03:05:06+00:00 heroku[web.1]: Process exited
2012-01-04T03:05:11+00:00 heroku[router]: Error H10 (App crashed) -> GET floating-stone 5077.heroku.com/ dyno= queue= wait= service= status=503 bytes=
Earlier in the log I see the following errors as well:
WARNING: Invalid .gemspec format in '/app/.bundle/gems/ruby/1.9.1/specifications/rails-3.2.0.rc1.gemspec'
WARNING: Invalid .gemspec format in '/app/.bundle/gems/ruby/1.9.1/specifications/actionmailer-3.2.0.rc1.gemspec'
WARNING: Invalid .gemspec format in '/app/.bundle/gems/ruby/1.9.1/specifications/actionpack-3.2.0.rc1.gemspec'
my gemfile is as follows:
source 'https://rubygems.org'
gem 'rails', '3.2.0.rc1'
# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'
gem 'mysql2'
# Gems used only for assets and not required
# in production environments by default.
group :assets do
gem 'sass-rails', '~> 3.2.0'
gem 'coffee-rails', '~> 3.2.0'
#gem 'uglifier', '>= 1.0.3'
end
gem 'jquery-rails'
group :development do
gem 'rspec-rails', '2.7.0'
gem 'ZenTest', '4.6.2'
gem 'autotest-growl'
gem 'autotest-fsevent'
gem 'webrat', '0.7.3'
end
group :test do
gem 'rspec', '2.7.0'
gem 'webrat', '0.7.3'
end
I am having trouble debugging the issue and looked through almost all of the rails/heroku posts I could find but nothing on this specific issue. I was looking for some help...apologies if this is something quite basic.
I should also mention that the app works fine on my local machine and here is my database information (I am using mysql). Here is the DB info.
# MySQL. Versions 4.1 and 5.0 are recommended.
#
# Install the MYSQL driver
# gem install mysql2
#
# Ensure the MySQL gem is defined in your Gemfile
# gem 'mysql2'
#
# And be sure to use new-style password hashing:
# http://dev.mysql.com/doc/refman/5.0/en/old-client.html
development:
adapter: mysql2
encoding: utf8
reconnect: false
database: sample_app_development
pool: 5
username: root
password:
socket: /tmp/mysql.sock
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
adapter: mysql2
encoding: utf8
reconnect: false
database: sample_app_test
pool: 5
username: root
password:
socket: /tmp/mysql.sock
production:
adapter: mysql2
encoding: utf8
reconnect: false
database: sample_app_production
pool: 5
username: root
password:
socket: /tmp/mysql.sock
Thanks!

Answer 1

The live version of new rails is available now ... i think you should give a try to rails 3.1.3 mature version ... this seem to come configuration issue as i am running my apps perfectly with rails 3.1.3 in heroku.

Answer 2

Does your Gemfile.lock file mention this version of ActiveModel? Have you done a full bundle update rails / bundle install, then committed the file and re-deployed?

Answer 3

I had this same problem. What worked in development locally, did not work when I deployed to Heroku. It is likely that you have a gem that is locked to an older version of Rails (or ActiveSupport as was my case.) Review your Gemfile.lock file. You may will likely find a reference to an older version of a Rails component.
Should you find this to be true, try commenting out the gem and see if your app will run when you deploy to Heroku. If so, then review the GitHub forks of the offending gem to see if someone has a solution. If you find an alternative, specify the git repository in your gem file and then run bundle install.
e.g.
gem 'tinymce-rails', :git => 'git://github.com/spohlenz/tinymce-rails.git'