On Wed, 2013-09-11 at 17:28 +0100, Duncan Coutts wrote:
Further, if only ghc-pkg and the ghc build system depend on Cabal, then it is easier for Cabal to add more dependencies, since they do not have to be installed with ghc (due to the ghc lib depending on them). In particular the Cabal folks would like to use a proper parser and have suggested adding dependencies on parsec, mtl and transformers. If only ghc-pkg depends on Cabal, then these dependencies only need to be used at build time, and do not have to be installed (which also means they don't have to be kept quite so up to date).
Actually, this is not quite right. Since ghc would still ship Cabal (but not depend on it), it would also ship its dependencies including parsec, mtl and transformers. So they would need to be up to date and installed, it's just that ghc itself would not depend on them. If that's really inconvenient, it's plausible to have a minimal set which is just the things ghc depends on, so long as what gets shipped to users is the useful set, including Cabal. Duncan