[Haskell-cafe] Cabal: top level dependency base -any

[Jacek Generowicz]

On 2011 May 24, at 09:28, Ivan Lazar Miljenovic wrote:

> On 24 May 2011 16:57, Jacek Generowicz <jacek.generowicz at cern.ch>  
> wrote:
>> Hi,
>>
>> Could anyone shed light on the meaning of this error message?
>>
>> cabal: cannot configure xmonad-0.9.1 It requires base ==3.*
>> For the dependency on base ==3.* there are these packages:  
>> base-3.0.3.1 and
>> base-3.0.3.2. However none of them are available.
>> base-3.0.3.1 was excluded because of the top level dependency base - 
>> any
>> base-3.0.3.2 was excluded because of the top level dependency base - 
>> any
>> [...]
>> Any hints?
>
> Yes: use xmonad-0.9,2 instead!  It supports base-4, which is probably
> what you have (with GHC-7.0.*).

Indeed, I discovered that to be the solution in the meantime, as I  
noticed that on my other system xmonad-0.9.2 was being installed by  
cabal install. Doing a cabal update made everything go through (with  
xmonad-0.9.2).

Which makes me wonder why the two systems had different ideas of what  
the most recent xmonad version was, as I installed both of them  
yesterday afternoon. I seem to be discovering a rule of thumb: do a  
cabal update *every time* you want to cabal install.

Anyway, thanks for the hint.