[Haskell-cafe] Re: circular dependencies in cabal

[Duncan Coutts]

On Mon, 2009-02-02 at 19:16 -0800, Valentyn Kamyshenko wrote:
> Hi Duncan,
> 
> The major problem that I see is with
>   # cabal update
>   # cabal upgrade
> sequence of operations (that is, upgrading all installed packages).

Right, that's exactly what doesn't work well and that I'm proposing to
temporarily disable.

> I use this regularly to keep packages that I use (or are going to use)  
> up to date.
> This is the functionality that, I suppose, everybody expects from the  
> system like hackage/cabal.
> 
> And, so far as I can see, the major problem is that 'cabal upgrade'  
> will happily upgrade packages, that the core package depends on, and  
> eventually will create configuration with circular dependencies.
> Can we do something simple - like, for example, forbidding updates of  
> the packages that the core depends on (directly and indirectly)?

Yes and there are a couple of additional ways we could improve it. But
I'm thinking it'd be better to release before those things are done, and
so in the mean time disable upgrade. In the mean time we can make it
list the available packages that are newer than the installed ones and
you get to pick manually which ones are sensible to install.

Duncan