On 2011 May 24, at 09:28, Andres Loeh 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
It's not a great error message. Yes, xmonad-0.9.1 requires base ==3.*. So far, so good. Now, base is a special package. It comes with ghc, and cannot be upgraded. That's why Cabal will rule out all base versions but the one you already have installed. If you have a recent ghc, that'll be base-4.
So Cabal is correct to fail in this case: you cannot install this version of xmonad with this version of ghc.
That makes sense. Thanks your the explanation. So would it be correct to infer that the -any restriction will only (and always) come into play with special packages such as base? Are there any other special packages besides base?