What you've done is correct.  Unlike Gemfiles, gemspecs do not autorequire other gems; that has to be handled explicitly by the gem.  This makes sense, because gems don't always need *all* the gems they depend on in *all* situations, and load order can matter, so this is left to the gem creators' discretion.

I did put a lot of the require calls in lib/wagn/all.rb, but that was a bit of a hack to get things working in the gem.