cabal beginner issues (other-modules, build-depends)
simonmar at microsoft.com
Fri Sep 23 04:52:05 EDT 2005
On 22 September 2005 23:02, Andrew Pimlott wrote:
> 2. Similar comments apply to build-depends. I wrote a module Foo.hs:
> module Foo (foo) where
> import Control.Monad.Identity
> foo = runIdentity (return ())
> and a cabal file (working from an example obviously):
> Name: foo
> Version: 1.1
> License: BSD3
> Build-Depends: base
> This built and installed without error, but when I created another
> module that imports Foo and tried to compile it with "ghc
> --make", I got undefined references to Control.Monad.Identity.
> Eventually, I found that I need to add mtl to build-depends.
> Again it would have been better to get an error during package
> creation, and this was particulary tricky to figure out because
> "build-depends" sounds like it should only affect package at
This is fixed in newer versions of Cabal when used with newer versions
of GHC (6.4.1). Missing dependencies are now reported as build errors,
because GHC is invoked with the -hide-all-packages option.
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