[darcs-users] git-darcs-import - howto base4

Sittampalam, Ganesh ganesh.sittampalam at credit-suisse.com
Tue Dec 8 13:25:29 UTC 2009

Marc Weber wrote:

> Right now darcs appear to be a burden to me because I have to
> maintain it as well when working with many haskell packages. 
> Today I spend some more time improving the hack-nix system. Now I can
> even fetch and update darcs libraries automatically. 

That sounds pretty nice, and is something I was thinking of playing with
at some point for automatically building darcs in multiple

> However one point is bothering me: darcs is using base-3 by default.
> Using most up to date versions on hackage there is no solution to
> build darcs without tweaking many .cabal files. This is all due the
> base-3 constraint. So what about dropping it and going base4? What's
> the reason for not having done it yet?  

I hadn't actually even noticed the issue, to be honest. I guess because
darcs is normally used as an application it doesn't typically bite.

> The patch file I posted earlier already contained a quick hack using
> CPP to use Control.Exception or Control.OldExceptions depending on
> base version.  
> It seemed to work. However there is anther alternative: Using
> extensible excpetion package from hackage. Then the new Exceptions
> can be used with  
> base3 as well AFAIK.
> What do you prefer?
> How would you make darcs work with base4 ?

extensible-exceptions is the best solution, IMO - it centralises the CPP
hackery in one place.

We should definitely fix this constraint and I'll try to prioritise
reviewing any patch that does it.



 Please access the attached hyperlink for an important electronic communications disclaimer: 

More information about the darcs-users mailing list