This is superfluous:
Goal prefix is specified as: 'versions'. Maven currently expects it to be 'versions'.
Fixed in r691149.
Next release is 2.5, due to large changes in ant support, and addition of PluginToolsRequest to allow shunting around of extra params in the future...used this to add encoding, for example.
FTR I'm using version 2.9 and I still get this warning:
[WARNING] Goal prefix is specified as: 'xar'. Maven currently expects it to be 'xwiki-commons-tool-xar'.
<!-- This to allow calling mvn xar:<mojo> from the command line. For example mvn xar:format
Without this users would need to call mvn xwiki-commons-tool-xar-plugin:format -->
Should I reopen this issue or clone a new one?