capistrano-ext multistage:prepare doesn't work

Hi,

I couldn't find any documentation for capistrano-ext anywhere, so I
looked through the source...

There is a multistage:prepare method which seems to be designed to
create stub deploy files for the stages. The problem is that it
doesn't work if the files don't already exist, because multistage.rb
will already have crashed by that point by trying to load the non-
existent files.

If you touch the missing files first, multistage:prepare puts the stub
content in them OK.

The error message, to help future Googlers:

$ cap staging multistage:prepare
  * executing `staging'
/opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/capistrano/
configuration/loading.rb:184:in `find_file_in_load_path': no such file
to load -- config/deploy/staging (LoadError)
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/
capistrano/configuration/loading.rb:172:in `load_from_file'
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/
capistrano/configuration/loading.rb:89:in `load'
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/
capistrano/configuration/loading.rb:86:in `load'
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/
capistrano/configuration/loading.rb:86:in `each'
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/
capistrano/configuration/loading.rb:86:in `load'
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-ext-1.2.0/lib/
capistrano/ext/multistage.rb:13
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/
capistrano/configuration/execution.rb:80:in `instance_eval'
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/
capistrano/configuration/execution.rb:80:in
`execute_task_without_callbacks'
         ... 7 levels...
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/lib/
capistrano/cli/execute.rb:14:in `execute'
        from /opt/local/lib/ruby/gems/1.8/gems/capistrano-2.1.0/bin/cap:4
        from /opt/local/bin/cap:16:in `load'
        from /opt/local/bin/cap:16


Jon