While the GHC library currently has a `.cabal` file, the information that it captures is not sufficient to build the package as a "normal" Haskell package. Consequently, `ghc` must be built using the GHC build system and the rest of the ecosystem (e.g. `cabal-install`) considers it to be non-reinstallable. This has a few unfortunate implications: * users of the GHC API must use precisely the dependency packages that `ghc` links against * GHC binary distributions must ship the `ghc` library in every conceivable way that the user might need However there is no good reason why `ghc` *can't* be made to be reinstallable and shipped as a normal Hackage package (with some restrictions). Specifically, this involves: * moving all of the ad-hoc compiler flags encoded in the build system into the `.cabal` file * moving any code generation logic from the build system into a custom `Setup.hs`