I am working on my first .cabal file for a project I am working on. I am working in a sandbox, and I have installed the following set of packages using cabal install (in that order):
$ cabal install repa
Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: repa (user goal)
rejecting: repa-3.2.3.3, 3.2.3.2, 3.2.3.1 (conflict: MonadPrompt =>
rejecting: repa-3.2.2.201204.1 (conflict: MonadPrompt =>
rejecting: repa-3.2.2.3, 3.2.2.2, 3.2.2.1 (conflict: MonadPrompt =>
rejecting: repa-3.2.1.1, 3.1.4.2, 3.1.4.1, 3.1.3.3, 3.1.3.2, 3.1.3.1, 3.1.2.1,
ghc-prim==0.2.*)
rejecting: repa-3.1.0.1, 3.0.0.1 (conflict: MonadPrompt =>
rejecting: repa-2.2.0.1, 2.1.1.6 (conflict: MonadPrompt =>
rejecting: repa-2.1.1.5 (conflict: MonadPrompt =>
rejecting: repa-2.1.1.4 (conflict: MonadPrompt =>
rejecting: repa-2.1.1.3, 2.1.1.2, 2.1.1.1, 2.1.0.1, 2.0.2.1, 2.0.1.1, 2.0.0.4,
2.0.0.3, 2.0.0.2, 2.0.0.1 (conflict: base =>
trying: repa-1.1.0.0
next goal: dph-prim-seq (dependency of repa-1.1.0.0)
rejecting: dph-prim-seq-0.7.0.1, 0.6.1.1, 0.6.0.1, 0.5.1.1 (conflict: repa =>
dph-prim-seq==0.4.*)
Dependency tree exhaustively searched.
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.
However, if I clone the repa repository, cd repa/repa && cabal install, that seems to work.
As I said, I am new to cabal. Is there something I am doing wrong or is there a dependency issue that has not been worked out in the switch to GHC 7.8.2?