[Haskell-beginners] Cabal dependencies problem

[Daniel Fischer]

On Tuesday 22 February 2011 11:43:03, Jun HU wrote:
> Hello everyone,
>
> I've some problems with cabal dependency mechanism. For example,
> when i try to install package "funsat",

>
> while the current array package is on version array-0.3.0.2.  The
> package has back compatibility problem.  Any advice is appreciated... 

For funsat, you can try

$ cabal install funsat-0.6.0

Version 0.6.0 doesn't have the explicit dependency on array-0.2.* and 
containers-0.2.*, so it should work (and it built on hackage with 6.12).

Generally, when a package doesn't build because of restrictive 
dependencies, you can try the following:

$ cabal unpack problem-package
$ cd problem-package
-- Edit the .cabal file, adjust dependencies and don't forget to bump the 
version number (append a '.1' to it). If you don't increment the version 
number, cabal might want to reinstall the package when you build a library 
depending on it.
-- take a deep breath and cross your fingers
$ cabal install

If there are compilation errors, it might or might not be worth trying to 
fix the code.

In any case, notify the maintainer of the dependency problem, if you 
modified the .cabal and it worked, tell the maintainer that it did.

> thank you in advance.
>
> Sincerely,
>
> Jun