Cabal and external dependencies

Is cabal capable of detecting missing external deps, e.g. for packages that provide bindings? Does this depend on package authors and some use of a config script seperate to .cabal? I'm just curious because I ran into this just now -- I tried to install dons' hackage-sparklines with cabal-install today (whilst reading his blog post about the same) which failed, in a way that seemed cryptic at first. I needed to notice that it was gd which failed and guess that I should install the libgd dev files. It's obvious that I would need these, you might say, but it certainly has the potential to confuse people... Jim