GHC Error in linker "undeined reference"

[Esa Ilari Vuokko]

Hi,

On 8/12/06, Johan Grönqvist <johan.gronqvist at gmail.com> wrote:
> import Control.Monad.State
> import Control.Monad.ST
> import Data.Array.ST
> import Data.List

Control.Monad.State is from package mtl, the other modules are part
of the base package, I think.

> ubuntu at ubuntu:~/haskell/Forth$ ghc forth.lhs

You need to tell ghc that you want to link package mtl.

ghc -package mtl forth.lhs
or more automatic
ghc --make forth.lhs

The packages you can import without any additional options are
the packages "ghc-pkg list" shows as visible.  But without --make, or
explicitly telling, ghc doesn't know which packages to link with.

HTH,
--Esa