Do I ever want to install a package outside of a sandbox?

Question

After 3 months of using Haskell, I just realized that I shouldn't use cabal as a package manager.

Now my question is do I ever want to install a package outside of a sandbox? If yes, why?

Answer 1

I often muck around with ideas that aren't full packages. They're often a single file, around 30-100 lines, don't have a main, aren't libraries, and are never intended to be used as anything other than toys to load in ghci. Occasionally, they depend on libraries from packages that don't come with ghc. I'll just install packages they depend on in my user db, because who cares? Worst case, I'll nuke ~/.ghc and reinstall what I need for whatever I work on next.