title: Heroku Bundle Error
body: <p>So heroku has trouble bundling my app when using the command: </p>
  
  <pre><code>$ git push heroku master
  </code></pre>
  
  <p>It is no problem when I bundle locally </p>
  
  <pre><code>$ bundle update
  </code></pre>
  
  <p>And I have made commits and added Gemfile and Gemfile.lock
  Any idea why I get this error?</p>
  
  <pre><code>$ git push heroku master
  Counting objects: 25, done.
  Delta compression using up to 4 threads.
  Compressing objects: 100% (22/22), done.
  Writing objects: 100% (22/22), 2.65 KiB, done.
  Total 22 (delta 16), reused 0 (delta 0)
  
  -----&gt; Removing .DS_Store files
  -----&gt; Ruby/Rails app detected
  -----&gt; Using Ruby version: ruby-1.9.3
  -----&gt; Installing dependencies using Bundler version 1.3.0.pre.5
         Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin
         Fetching gem metadata from https://rubygems.org/.......
         Fetching gem metadata from https://rubygems.org/..
  /app/slug-compiler/lib/utils.rb:66:in `block (2 levels) in spawn': command='/app/slug-compiler/lib/../../tmp/buildpacks/ruby/bin/compile /tmp/build_2c5mcld95eb34 /app/tmp/repo.git/.cache' exit_status=0 out='' at=timeout elapsed=900.1125066280365 (Utils::TimeoutError)
      from /app/slug-compiler/lib/utils.rb:52:in `loop'
      from /app/slug-compiler/lib/utils.rb:52:in `block in spawn'
      from /app/slug-compiler/lib/utils.rb:47:in `popen'
      from /app/slug-compiler/lib/utils.rb:47:in `spawn'
      from /app/slug-compiler/lib/buildpack.rb:37:in `block in compile'
      from /app/slug-compiler/lib/buildpack.rb:35:in `fork'
      from /app/slug-compiler/lib/buildpack.rb:35:in `compile'
      from /app/slug-compiler/lib/slug.rb:497:in `block in run_buildpack'
      from /app/slug-compiler/lib/utils.rb:121:in `log'
      from /app/slug-compiler/lib/slug.rb:748:in `log'
      from /app/slug-compiler/lib/slug.rb:496:in `run_buildpack'
      from /app/slug-compiler/lib/slug.rb:125:in `block (2 levels) in compile'
      from /app/slug-compiler/lib/utils.rb:102:in `block in timeout'
      from /usr/local/lib/ruby/1.9.1/timeout.rb:58:in `timeout'
      from /app/slug-compiler/lib/utils.rb:102:in `rescue in timeout'
      from /app/slug-compiler/lib/utils.rb:97:in `timeout'
      from /app/slug-compiler/lib/slug.rb:114:in `block in compile'
      from /app/slug-compiler/lib/utils.rb:121:in `log'
      from /app/slug-compiler/lib/slug.rb:748:in `log'
      from /app/slug-compiler/lib/slug.rb:113:in `compile'
      from /app/slug-compiler/bin/slugc:85:in `block in &lt;main&gt;'
      from /app/slug-compiler/lib/slug.rb:505:in `block in lock'
      from /app/slug-compiler/lib/repo_lock.rb:44:in `call'
      from /app/slug-compiler/lib/repo_lock.rb:44:in `run'
      from /app/slug-compiler/lib/slug.rb:505:in `lock'
      from /app/slug-compiler/bin/slugc:66:in `&lt;main&gt;'
   !     Heroku push rejected, failed to compile Ruby/rails app
  
  To git@heroku.com:app_name.git
   ! [remote rejected] master -&gt; master (pre-receive hook declined)
  error: failed to push some refs to 'git@heroku.com:app_name.git'
  </code></pre>
  
  <p>This is my gem file:</p>
  
  <pre><code>source 'https://rubygems.org'
  ruby '1.9.3'    
  
  gem 'rails'
  # Gems used only for assets and not required
  # in production environments by default.
  group :assets do
        gem 'less-rails-bootstrap'
        gem 'less-rails'
        gem 'less'
        gem 'therubyracer'
        gem 'jquery-ui-rails' 
        gem 'sass-rails',   '~&gt; 3.2.3'
        gem 'coffee-rails', '~&gt; 3.2.1'
        gem 'uglifier', '&gt;= 1.0.3'
  end
  
  group :development, :test do
        gem 'rspec-rails'
        gem 'factory_girl_rails'
        gem 'sqlite3'
  end
  
  group :test do
        gem "email_spec"
        gem 'faker'
        gem 'capybara'
        gem 'guard-rspec'
        gem 'launchy'
  end
  
  # Allow æ,ø,å in strings
  gem 'magic_encoding'
  
  # Files uploading gem
  gem 'carrierwave'
  
  # Spreadsheet parser gem
  gem 'roo'
  
  # Calendar Event Export
  gem 'icalendar'
  
  # Authentication gems
  gem 'devise'
  gem 'devise_invitable'
  gem "cancan"
  
  # Calendar features
  gem 'event-calendar', :require =&gt; 'event_calendar'
  gem 'bootstrap-sass'
  gem 'nested_form'
  gem 'ransack'
  gem 'bootstrap-datepicker-rails'
  gem 'jquery-rails' 
  </code></pre>
  
  <p>Any tips on how to solve this error will be much appreciated.</p>