[Haskell-cafe] cabal-install to produce a dependency tree

Dear Cafe, What would be the easiest way of generating the following output, given a package name optionally with additional constraints? $- foo "X > 3" "X > 3" depends on A-2.2, B-1.0, C-1.2 A-2.2 depends on D-1.2.3 ... I assume cabal-install internally does this anyway while creating the installation plan, so is there an easy way to get this info out of cabal install? Thanks, Ozgur