[Haskell-cafe] Mystified by Cabal
Colin Paul Adams
colin at colina.demon.co.uk
Sat Mar 7 12:18:24 EST 2009
I have just attempted Cabal-izing my program (splitting it into a
library and main program as well), and I'm mystified by some problems
I am having.
First, when I try to build the library I get:
[colin at susannah game-tree]$ runhaskell Setup build
Preprocessing library game-tree-18.104.22.168...
Data/Tree/Game/Negascout.hs:31:0: Unrecognised pragma
[1 of 2] Compiling Data.Tree.Game.Tree ( Data/Tree/Game/Tree.hs, dist/build/Data/Tree/Game/Tree.o )
Failed to load interface for `Prelude':
it is a member of package base-22.214.171.124, which is hidden
That mystifies me. Googling, it appears to be a common error in the
past, but none of the reasons apparently apply to my
case. Incidentally, Tree.hs imports nothing. It just looks like:
-- | Nodes in game trees
-- Copyright 2009 Colin Adams
-- This file is part of game-tree.
-- Game-tree is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
-- Game-tree is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
-- You should have received a copy of the GNU General Public License
-- along with game-tree. If not, see <http://www.gnu.org/licenses/>.
module Data.Tree.Game.Tree where
-- | Nodes in a game search tree
class Tree a where
-- | Is this a game-terminating node (e.g. checkmate)?
is_terminal :: a -> Bool
-- | Heuristic value of node
node_value :: a -> Int
-- | Child nodes in the game tree (positions more deeply searched)
children :: a -> [a]
So I couldn't build my program using runhaskell, as I couldn't install
the library. Instead, i tried ghc --make instead with the -idir
option. It looks in the right place, but still doesn't recognise the
Chasing modules from: *Chu-shogi.hs
Could not find module `Data.Tree.Game.Tree':
What am I doing wrong?
Perhaps Cabal should be named Caballa instead.
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