Rails 3.1 assets pipleline and missing finger print information

HI I have just upgraded from 3.0 to 3.1.1 all seems to be working. When deploy to production I replaced jammit with the assets:precompile 开发者_开发百科task in capistrano (after deploy:update_code). The assets (JS only) gets minfy great into one file. But from reading the documentation the file should also have a finger print -.js for braking the cache. However I am not getting it :(

Any help will be really useful :)

Do you have the following in your configuration file?

# True means use fingerprinting
config.assets.digest = true