deploy:assets:precompile insists on running on production environment in capistrano

You want to deploy your rails 3.2 application to another environment except production, but the default capistrano recipe for precompiling the assets keeps using the production environment as in:

 * executing `deploy:assets:precompile'
  * executing "cd /var/www/dev/app/releases/20120816130649 && rake RAILS_ENV=production RAILS_GROUPS=assets assets:precompile"
    servers: [""]

Add the following environment option in your deploy/other_env.rb file:

set :rails_env, "other_env"