rake assets:precompile RAILS_ENV=production not working as required

Question

I am trying to precompile assets using the command rake assets:precompile RAILS_ENV=production , but I always get the error below.

** Invoke assets:precompile (first_time)
    ** Execute assets:precompile
    /usr/bin/ruby /usr/bin/rake assets:precompile:all RAILS_ENV=production RAILS_GROUPS=assets --trace
    ** Invoke assets:precompile:all (first_time)
    ** Execute assets:precompile:all
    ** Invoke assets:precompile:primary (first_time)
    ** Invoke assets:environment (first_time)
    ** Execute assets:environment
    ** Invoke environment (first_time)
    ** Execute environment
    ** Invoke tmp:cache:clear (first_time)
    ** Execute tmp:cache:clear
    ** Execute assets:precompile:primary
    rake aborted!
    LoadError: cannot load such file -- uglifier
      (in /home/cool_tech/cool_tech/app/assets/javascripts/application.js)
    /usr/lib/ruby/gems/2.0.0/gems/activesupport-3.2.14/lib/active_support/dependencies.rb:251:in `require'
    /usr/lib/ruby/gems/2.0.0/gems/activesupport-3.2.14/lib/active_support/dependencies.rb:251:in `block in require'
    /usr/lib/ruby/gems/2.0.0/gems/activesupport-3.2.14/lib/active_support/dependencies.rb:236:in `load_dependency'
    /usr/lib/ruby/gems/2.0.0/gems/activesupport-3.2.14/lib/active_support/dependencies.rb:251:in `require'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/compressors.rb:31:in `registered_js_compressor'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/bootstrap.rb:18:in `block in run'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/compressors.rb:80:in `call'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/compressors.rb:80:in `compressor'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/compressors.rb:74:in `compress'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/processing.rb:265:in `block in js_compressor='
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/processor.rb:29:in `call'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/processor.rb:29:in `evaluate'
    /usr/lib/ruby/gems/2.0.0/gems/tilt-1.4.1/lib/tilt/template.rb:103:in `render'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/context.rb:193:in `block in evaluate'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/context.rb:190:in `each'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/context.rb:190:in `evaluate'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/bundled_asset.rb:26:in `initialize'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:252:in `new'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:252:in `build_asset'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/index.rb:93:in `block in build_asset'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/caching.rb:19:in `cache_asset'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/index.rb:92:in `build_asset'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:169:in `find_asset'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/index.rb:60:in `find_asset'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/static_compiler.rb:19:in `block in compile'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:219:in `block in each_logical_path'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:206:in `block (2 levels) in each_file'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:196:in `each'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:196:in `each_entry'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:204:in `block in each_file'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:203:in `each'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:203:in `each_file'
    /usr/lib/ruby/gems/2.0.0/gems/sprockets-2.2.2/lib/sprockets/base.rb:217:in `each_logical_path'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/static_compiler.rb:18:in `compile'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/assets.rake:56:in `internal_precompile'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/assets.rake:70:in `block (3 levels) in <top (required)>'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:240:in `call'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:240:in `block in execute'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:235:in `each'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:235:in `execute'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
    /usr/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:165:in `invoke'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/assets.rake:60:in `block (3 levels) in <top (required)>'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:240:in `call'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:240:in `block in execute'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:235:in `each'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:235:in `execute'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
    /usr/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:165:in `invoke'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:150:in `invoke_task'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:106:in `each'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:106:in `block in top_level'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:115:in `run_with_threads'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:100:in `top_level'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:78:in `block in run'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:176:in `standard_exception_handling'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:75:in `run'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/bin/rake:33:in `<top (required)>'
    /usr/bin/rake:23:in `load'
    /usr/bin/rake:23:in `<main>'
    Tasks: TOP => assets:precompile:primary
    rake aborted!
    Command failed with status (1): [/usr/bin/ruby /usr/bin/rake assets:precomp...]
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/file_utils.rb:54:in `block in create_shell_runner'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/file_utils.rb:45:in `call'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/file_utils.rb:45:in `sh'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/file_utils_ext.rb:37:in `sh'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/file_utils.rb:82:in `ruby'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/file_utils_ext.rb:37:in `ruby'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/assets.rake:12:in `ruby_rake_task'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/assets.rake:21:in `invoke_or_reboot_rake_task'
    /usr/lib/ruby/gems/2.0.0/gems/actionpack-3.2.14/lib/sprockets/assets.rake:29:in `block (2 levels) in <top (required)>'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:240:in `call'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:240:in `block in execute'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:235:in `each'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:235:in `execute'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
    /usr/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/task.rb:165:in `invoke'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:150:in `invoke_task'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:106:in `each'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:106:in `block in top_level'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:115:in `run_with_threads'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:100:in `top_level'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:78:in `block in run'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:176:in `standard_exception_handling'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/lib/rake/application.rb:75:in `run'
    /usr/lib/ruby/gems/2.0.0/gems/rake-10.2.2/bin/rake:33:in `<top (required)>'
    /usr/bin/rake:23:in `load'
    /usr/bin/rake:23:in `<main>'
    Tasks: TOP => assets:precompile

Does anybody has any idea what could be wrong? Thanks.

Answer 1

Replace

rake assets:precompile RAILS_ENV=production

with

rake assets:precompile ( RAILS_ENV=production bundle exec rake assets:precompile is the exact rake task)

Since precompilation is done in production mode only, no need to explicitly specify the environment.

Update:

Try adding the below line to your Gemfile:

group :assets do
  gem 'therubyracer'
  gem 'sass-rails', "  ~> 3.1.0"
  gem 'coffee-rails', "~> 3.1.0"
  gem 'uglifier'
end

Then run bundle install .

Hope it will work :)

Answer 2

Have you added this gem to your gemfile?

# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'

move that gem out of assets group and then run bundle again, I hope that would help!

Answer 3

To explain the problem, your error is as follows:

LoadError: cannot load such file -- uglifier
      (in /home/cool_tech/cool_tech/app/assets/javascripts/application.js)

This means somewhere in application.js , your app is referencing uglifier (probably in the manifest area at the top of the file). To fix the issue, you either need to remove the reference to uglifier , or make sure the uglifier file is present in your app, hence the answers you've been provided

---

Fix

If you've had no luck with adding the gem to your GemFile, a quick fix would be to remove any reference to uglifier in your application.js manifest. This, of course, will be temporary, but will at least allow you to precompile your assets

Answer 4

I found out that my back-up project worked well if I precompile without bundle update . Maybe something went wrong with gem updated but I don't know which gem has an error.

Answer 5

I had this problem today. I fixed it being being explict about my require

gem 'uglifier', '>= 1.0.3', require: 'uglifier'

I had mine still in the assets group.