Re: [Haskell-cafe] Hackage on Linux

On 24 August 2010 21:18, Joachim Breitner wrote:

Hi,

Am Dienstag, den 24.08.2010, 09:30 +0100 schrieb Magnus Therning:

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On Tue, Aug 24, 2010 at 06:50, Mathew de Detrich wrote:

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- in some situations doing a general update with arch (through clyde or packer)  breaks ghc (last time it happened packer tried to uninstall/update arch packages which failed because those packages had dependencies. The files got removed but since unregister failed ghc thought they still existed)

This is arguably an error in the Arch packages.  The dependencies aren't quite as strict as they really should be.  I've taken the approach of never letting pacman update any haskell-* package.  Instead I do a small song-and-dance where I first remove the packages in question, and any package that depends on them, then I re-install what I just removed.

In Debian, this cannot happen any more, as libraries are tied to the packages of their dependencies via the ABI hash used by ghc. (If I am correctly understanding the symptoms). So using apt-get upgrade will never break any Debian-installed packages.

Interesting; I've been discussing with Ciaran McCreesh on a possibility of getting something like that into Paludis for use with Exherbo (a few non-Haskell related things are starting to annoy me with the petty politics, etc. of Gentoo and Exherbo has some really nice ideas). How exactly do you do this? Register the ABI hash upon installation and check if it ever changes? Or is this all done when you build the package since Debian uses binary packages?

OTOH, you cannot expect Debian to always and immediately install the latest Cabal versions – there are possibly good reasons for not upgrading.

Yes, least of which is someone spending the time to notice that a package is out of date and bothering to update it + test that update (including any packages that depend upon it). -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com