Re: [Haskell-cafe] Hackage -> MacPorts?

duncan.coutts:

On Thu, 2008-09-04 at 12:09 -0400, David Menendez wrote:

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On Thu, Sep 4, 2008 at 5:19 AM, Duncan Coutts wrote:

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That's exactly the same situation as with Gentoo. We provide a ghc-updater program that re-installs all the existing libs for the new ghc. Gentoo also only provides libs for ghc.

That's more convenient than re-installing all the libs by hand. I guess that's good enough for non-developer use; someone who just wants to install a program doesn't need to have more than one version of GHC installed, for example. It pains me to see the assumption that Haskell = GHC built in to our distribution methods, though.

Yeah, I know. It's really a limitation of systems like Gentoo. Gentoo's position is that you should not encode things like this into the package name and provides a 'slotting' mechanism to allow multiple versions, however it's not quite expressive enough to slot on the haskell implementation and still get all the lib deps right.

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RPM apparently handles this by having the library packages install themselves under new names that include the environment name and version. I assume Nix can handle multiple Haskell environments.

Right. And yes, Nix can do everything because it's jolly cunning and takes the functional/persistent approach.

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Does anyone know whether arch linux and debian can handle multiple Haskell environments?

Debian does, again by encoding the haskell implementation name into the package name. I think arch only provides libraries for ghc.

That's right, on Arch we just go for what people actually need, i.e.: 1) 1 compiler, GHC 2) GHC comes with the core+extra set, so they're implicitly available 3) all other libs are "haskell-(map toLower packagename)" The complication to support multiple implementations et al isn't done by any other language group (i.e. libs aren't bundled for multiple python impls, or different C compilers), so I don't see why we should waste time on that either. Pragmatic, I know. -- Don