Cabal problem: cannot satisfy package-id ...

[Alistair Bayley]

(Is this the best place for cabal help?)

I'm trying to install Takusen and build the tests on an Ubuntu 10.4
machine, with haskell-platform 2010.1.0.0.1. Takusen itself built and
installed correctly. When building the tests I get this failure:

Building Takusen-0.8.7...
Building executable takusen_tests...
Creating dist/build/takusen_tests (and its parents)
Creating dist/build/takusen_tests/takusen_tests-tmp (and its parents)
/usr/bin/ghc --make -o dist/build/takusen_tests/takusen_tests
-hide-all-packages -fbuilding-cabal-package -no-user-package-conf
-package-conf dist/package.conf.inplace -i
-idist/build/takusen_tests/takusen_tests-tmp -i. -idist/build/autogen
-Idist/build/autogen -Idist/build/takusen_tests/takusen_tests-tmp
-optP-DUSE_NEW_EXCEPTIONS -optP-include
-optPdist/build/autogen/cabal_macros.h -odir
dist/build/takusen_tests/takusen_tests-tmp -hidir
dist/build/takusen_tests/takusen_tests-tmp -stubdir
dist/build/takusen_tests/takusen_tests-tmp -package-id
QuickCheck-2.1.0.3-c608a0a2c555bdf292cfea5b3273ac6b -package-id
base-4.2.0.0-2cc27b7e43511c4ca001642a7f77a8f6 -package-id
mtl-1.1.0.2-23ca4de7c573fd4df309067199a40634 -package-id
old-time-1.0.0.3-9efceb2bb905784e503d6cf147359f62 -package-id
random-1.0.0.2-cf650c34bae72c01e165a0d26c11236b -package-id
time-1.1.4-1ced433acd576e314843b083f147bc38 -package-id Takusen-0.8.7
-O -XCPP -XDeriveDataTypeable -XScopedTypeVariables ./Main.lhs
<command line>: cannot satisfy -package-id Takusen-0.8.7
    (use -v for more information)

(and that was the -v output)

There's no clue as to why "-package-id Takusen-0.8.7" cannot be
satisfied. "ghc-pkg list" shows the package (in the global database),
as does "cabal list Takusen".

Thanks,
Alistair