That'll build documentation for the current pwd's project (if there even is one), but that doesn't install and build the haddocks for dependencies. Well, unless you do `cabal install --only-dependencies` first, which brings us back to the original question.

I'm trying to get a local version of the documentation of all the packages I tend to use so I don't need to keep reaching out to hackage.haskell.org while developing [offline]. Easily enough done; I'm just trying to skip building the code which, in this sandbox, I don't need.

AfC