patch applied (cabal-install): Disable cabal upgrade and add cabal install --upgrade-dependencies

Peter Robinson thaldyron at
Wed Jun 2 06:32:19 EDT 2010

On 1 June 2010 18:52, Duncan Coutts <duncan.coutts at> wrote:
> On Tue, 2010-06-01 at 16:48 +0200, Peter Robinson wrote:
>> On 31 May 2010 15:18, Duncan Coutts <duncan.coutts at> wrote:
>> > Mon May 31 06:03:06 PDT 2010  Duncan Coutts <duncan at>
>> >  * Disable cabal upgrade and add cabal install --upgrade-dependencies
>> >  cabal upgrade now gives an error message telling people to use install
>> > or, if they know what they're doing, install --upgrade-dependencies
>> How about also adding a reference to 'cabal install world'? I think that's the
>> behaviour most people actually want when running upgrade (at least I do :) ).
> Yes, I was thinking about that. I think we need a little more work
> before the world feature is recommended to the masses.
> As you point out, we would really need to start tracking programs.

Yes, I guess tracking programs will be necessary, although this might not be as
urgent as the dep resolver problems. I suppose this is also highly
related to the
uninstall feature.

> The other thing I'm not yet convinced about is keeping just the flags in
> the world file. I suspect we'll need more eventually and should perhaps
> plan the format with that in mind. Also currently we do not properly
> assign flags to individual packages, that's not the fault of the world
> feature, it's a problem elsewhere in cabal-install.

You're probably right. For the time being, however, I would settle for
getting the simple file format to work without problems. :)

> Don't get me wrong, the world feature is definitely what we need (and
> works well for distros) but generally I think we need more experience of
> how it works in practise. I suspect one of the first things we'll find
> is that the dep resolver runs into problems when trying to install
> world. While it could find install plans for each package individually
> it might not be able to find a plan for all the world packages
> simultaneously. We may need some significant improvements in the solver
> and we might have to do things like treating the flags etc as
> suggestions rather than hard "all or nothing" constraints.

Hmm, yes I've noticed running into problems once the world file reaches
>10 lines. At the moment I don't really see how to make the current resolver
algorithm handle this issue, but I'll need to take a closer look at the code.


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