The current handling for this option works fine with Chef 11, but in Chef 10 this does not make possible to set the default value in knife.rb. There are many ways to fix it, but I think a good one would be to follow [this](http://docs.opscode.com/breaking_changes_chef_11.html#knife-configuration-parameter-changes) (with a fix for --no-options). I.e. remove the :default attribute here, and add methods:
```ruby
def locate_config_value(key)
  key = key.to_sym
  config[key].nil? ? Chef::Config[:knife][key] : config[key]
end

def provisioning_path
  locate_config_value(:provisioning_path) || '~/chef-solo'
end
```

I had a plan to unify the option handling overall after this issue is merged, but this is a good place start.