I am (again) running into cabal install issues; which have been all too common for me.

In this case as an example, I tried this:

       C:\Users\haskell>Cabal install buildwrapper

      …..

     buildwrapper-0.6.0 depends on regex-tdfa-1.1.8 which failed to install.

     regex-tdfa-1.1.8 failed during the building phase. The exception was:

     ExitFailure 1

So I tried this:

     C:\Users\haskell>cabal install regex-tdfa

     Resolving dependencies...

     In order, the following would be installed:

     regex-base-0.93.2 (reinstall) changes: array-0.3.0.2 -> 0.4.0.0, base-4.3.1.0

     -> 4.5.0.0, bytestring-0.9.1.10 -> 0.9.2.1, containers-0.4.0.0 -> 0.4.2.1,

     mtl-2.0.1.0 -> 2.1.2

     regex-tdfa-1.1.8 (new package)

     cabal: The following packages are likely to be broken by the reinstalls:

     regex-posix-0.95.1

     regex-compat-0.95.1

     haskell-platform-2011.3.0.0

     regex-posix-0.94.4

     regex-compat-0.93.1

     haskell-platform-2011.2.0.1

     regex-posix-0.95.1

     regex-compat-0.95.1

     haskell-platform-2012.2.0.0

     Use --force-reinstalls if you want to install anyway.

So what to do?

Last time I got into a situation like this I tried to start-over with cabal, remove all local cache and rebuild the library.

From a suggestion in SO; delete the ~/ghc & ~/cabal files and restart cabal, by a "cabal install cabal-install".

Didn’t help much, still stuck. Any hints?

I find that library issues like this with cabal are the biggest time-soak I have with using Haskell, and I usually have to abandon attempts to try some new library for various examples.

“Ghc-pkg check” lists lots of warnings, but all from haddock-html or haddock-interface; not sure what to make of that but I think it just means that somehow documentation was not installed for these packages.

>>cabal -V

cabal-install version 0.14.0

using version 1.14.0 of the Cabal library

GHCi version 7.4.1

HaskellPlatform-2012.2.0.0

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