gem yank - not working

Hi All,

I have distributes a gem. Now i want to remove it from the distribution.
So i have used "gem yank gemname -v version". But i'm getting the
following error.

ERROR: While executing gem ... (RuntimeError)
    Unknown command yank

The command "gem help commands" gives the following list, which doesn't
have "yank" command in it. Please guide me.

build Build a gem from a gemspec
    cert Manage RubyGems certificates and signing settings
    check Check installed gems
    cleanup Clean up old versions of installed gems in the
    contents Display the contents of the installed gems
    dependency Show the dependencies of an installed gem
    environment Display information about the RubyGems environment
    fetch Download a gem and place it in the current
    generate_index Generates the index files for a gem server
    help Provide help on the 'gem' command
    install Install a gem into the local repository
    list Display gems whose name starts with STRING
    lock Generate a lockdown list of gems
    mirror Mirror a gem repository
    outdated Display all gems that need updates
    owner Manage gem owners on
    pristine Restores installed gems to pristine condition from
                      located in the gem cache
    push Push a gem up to
    query Query gem information in local or remote
    rdoc Generates RDoc for pre-installed gems
    search Display all gems whose name contains STRING
    server Documentation and gem repository HTTP server
    sources Manage the sources and cache file RubyGems uses to
                      for gems
    specification Display gem specification (in yaml)
    stale List gems along with access times
    uninstall Uninstall gems from the local repository
    unpack Unpack an installed gem to the current directory
    update Update the named gems (or all installed gems) in
the local
    which Find the location of a library file you can

For help on a particular command, use 'gem help COMMAND'.

Commands may be abbreviated, so long as they are unambiguous.
e.g. 'gem i rake' is short for 'gem install rake'.



I got the command works.

We need to install "gemcutter". This will add "yank" to the list of gem

Then, we can use "gem yank gem_name -v version". It works.