I should add that I'd be fine with making pkg_add (without -U) for a package that is already installed an error. The argument for the current behavior is that such an error, while valid from some views, isn't useful to the human, who has told the pkg system that they want the package. For package managers using the tools, it seems to be less robust, but presumably they are coded to avoid this usage.
Attachment:
pgpdT_xTOqZcH.pgp
Description: PGP signature