rake assets:precompile RAILS_ENV=production not working as required

Question

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 🙂