title: heroku push error: "Could not detect rake tasks"
body: <p>I'm trying to deploy a basic app and it's not working. Using </p>
  
  <pre><code>git push heroku master 
  </code></pre>
  
  <p>I got this error message: </p>
  
  <pre><code>remote:  !     Could not detect rake tasks
  remote:  !     ensure you can run `$ bundle exec rake -P` against your app
  remote:  !     and using the production group of your Gemfile.
  remote:  !     rake aborted!
  remote:  !     LoadError: cannot load such file -- /tmp/build_a1cfcabff50107f84830d908386197b2/config/application
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/Rakefile:4:in `require'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/Rakefile:4:in `&lt;top (required)&gt;'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/rake_module.rb:28:in `load'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/rake_module.rb:28:in `load_rakefile'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:689:in `raw_load_rakefile'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:94:in `block in load_rakefile'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:176:in `standard_exception_handling'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:93:in `load_rakefile'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:77:in `block in run'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:176:in `standard_exception_handling'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:75:in `run'
  remote:  !     /tmp/build_a1cfcabff50107f84830d908386197b2/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/bin/rake:33:in `&lt;top (required)&gt;'
  remote:  !     vendor/bundle/bin/rake:16:in `load'
  remote:  !     vendor/bundle/bin/rake:16:in `&lt;main&gt;'
  remote:  !
  remote: /app/tmp/buildpacks/ruby/lib/language_pack/helpers/rake_runner.rb:102:in `load_rake_tasks!': Could not detect rake tasks (LanguagePack::Helpers::RakeRunner::CannotLoadRakefileError)
  </code></pre>
  
  <p><code>bundle exec rake -P </code> seems to be working fine.</p>
  
  <p>There's nothing special in my Gemfile, I just added Bootstrap:</p>
  
  <pre><code>source 'https://rubygems.org'
  
  
  # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
  gem 'rails', '4.2.5.1'
  
  # Use SCSS for stylesheets
  gem 'sass-rails', '~&gt; 5.0'
  # Use Uglifier as compressor for JavaScript assets
  gem 'uglifier', '&gt;= 1.3.0'
  # Use CoffeeScript for .coffee assets and views
  gem 'coffee-rails', '~&gt; 4.1.0'
  # See https://github.com/rails/execjs#readme for more supported runtimes
  # gem 'therubyracer', platforms: :ruby
  
  # Use jquery as the JavaScript library
  gem 'jquery-rails'
  # Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
  gem 'turbolinks'
  # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
  gem 'jbuilder', '~&gt; 2.0'
  # bundle exec rake doc:rails generates the API under doc/api.
  gem 'sdoc', '~&gt; 0.4.0', group: :doc
  
  gem 'bootstrap-sass' 
  # Use ActiveModel has_secure_password
  # gem 'bcrypt', '~&gt; 3.1.7'
  
  # Use Unicorn as the app server
  # gem 'unicorn'
  
  # Use Capistrano for deployment
  # gem 'capistrano-rails', group: :development
  #postgreeSQL for Heroku deployment
  
  
  group :development, :test do
    # Call 'byebug' anywhere in the code to stop execution and get a debugger console
    gem 'byebug'
    gem 'sqlite3'
  end
  
  group :development do
    # Access an IRB console on exception pages or by using &lt;%= console %&gt; in views
    gem 'web-console', '~&gt; 2.0'
  
  
    # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
    gem 'spring'
  end
  group :production do
    gem 'pg'
    gem 'rails_12factor'
  end
  ruby "2.2.3"
  </code></pre>
  
  <p>Well, I don't see why it's happening, since I have another project that is working normally. I checked everything and it still gives me that message.</p>