finding the dependecies of cabal packages

[Duncan Coutts]

On Wed, 2005-07-27 at 21:35 +0100, Duncan Coutts wrote:

> In particular the ebuild must list all the dependencies of the package.
> Required Haskell libraries are listed in the "build-depends:" field in
> the cabal file, so that one is easy. However it is not clear how to find
> out the build tools that the cabal package requires.
> 
> For example packages may require alex or happy or c2hs or other build
> time tools. Is there any better way to find if these tools are needed
> than to look through the source tree for any files with the appropriate
> extensions ".y", ".x", ".chs" etc?

And a similar follow up question is how do cabal packages specify
dependencies on particular versions of required tools? For example they
might depend on some feature in the latest version of a tool.

Duncan