Re: [Haskell-cafe] impoosible dependencies

On Wed, 20 Apr 2011 15:18:21 -0700, Rogan Creswick wrote:

On Wed, Apr 20, 2011 at 2:51 PM, Kevin Quick wrote:

...

$ cabal update $ cabal install hakyll Resolving dependencies... cabal: dependencies conflict: ghc-6.12.3 requires unix ==2.4.0.2 however unix-2.4.0.2 was excluded because ghc-6.12.3 requires unix ==2.4.1.0 $

Any advice (other than upgrading to 7.0.3, which is not an option at the moment)?

You can run the build with verbose output (--verbose=3) and get more details about why the impossible dependencies were required,

No joy: hakyll itself requires unix 2.4, so the following are discarded: unix-2.0, 2.2.0.0, 2.3.0.0, 2.3.1.0, 2.3.2.0, However, that's the only unix discard before the error occurs somewhat later on, only now the error is not with unix but with array (which is not discarded by anything): ... selecting text-0.11.0.5 (installed or hackage) and discarding text-0.11.0.0, 0.11.0.1, 0.11.0.2, 0.11.0.3, 0.11.0.4, 0.11.0.6 and 0.11.0.7 selecting deepseq-1.1.0.2 (installed or hackage) and discarding deepseq-1.1.0.0 and 1.1.0.1 selecting QuickCheck-2.4.0.1 (installed or hackage) and discarding QuickCheck-2.1, 2.1.0.1, 2.1.0.2, 2.1.0.3, 2.1.1, 2.1.1.1, 2.1.2, 2.2, 2.3, 2.3.0.1, 2.3.0.2 and 2.4 selecting cabal: dependencies conflict: ghc-6.12.3 requires array ==0.3.0.2 however array-0.3.0.2 was excluded because ghc-6.12.3 requires array ==0.3.0.1 $ Its starting to look like there's something very wrong with cabal databases. My first thought is to remove my local version, but I'm hesitant because I do have other haskell work I'm in progress on that isn't broken and I don't want to break it. :-)

or you can build your application (whatever relies on hakyll) with cabal-dev -- I've been able to build hakyll that way on my machine with ghc-6.12.3, so I suspect there is some unexpected dependency in your local package db that is causing cabal to make a series of undesirable version selections.

--Rogan

No joy there either. There were some preliminary package version complaints that I tried to resolve, but the end result is: $ cabal install cabal-dev Resolving dependencies... [1 of 1] Compiling Main ( /tmp/cabal-dev-0.7.4.113115/cabal-dev-0.7.4.1/Setup.hs, /tmp/cabal-dev-0.7.4.113115/cabal-dev-0.7.4.1/dist/setup/Main.o ) /tmp/cabal-dev-0.7.4.113115/cabal-dev-0.7.4.1/Setup.hs:7:47: Warning: In the use of `buildVerbose' (imported from Distribution.Simple.Setup): Deprecated: "Use buildVerbosity instead" Linking /tmp/cabal-dev-0.7.4.113115/cabal-dev-0.7.4.1/dist/setup/setup ... cabal: Error: some packages failed to install: cabal-dev-0.7.4.1 failed during the configure step. The exception was: ExitFailure 11 $ With --verbose=3 this appears to be post-link running cabal-dev itself: $ cabal install cabal-dev --verbose=3 ... *** Deleting temp files: Deleting: link: linkables are ... LinkableM (Wed Apr 20 16:14:58 MST 2011) main:Main [DotO /tmp/cabal-dev-0.7.4.113193/cabal-dev-0.7.4.1/dist/setup/Main.o] Linking /tmp/cabal-dev-0.7.4.113193/cabal-dev-0.7.4.1/dist/setup/setup ... *** Linker: ...[verbose GCC output elided]... rtend.o /nix/store/l8x3fdy1r6zf441vnqa87lzsvxrjbdz9-glibc-2.11.1/lib/crtn.o link: done *** Deleting temp files: Deleting: *** Deleting temp dirs: Deleting: /tmp/ghc13224_0 /tmp/cabal-dev-0.7.4.113193/cabal-dev-0.7.4.1/dist/setup/setup configure --verbose=3 --ghc --prefix=/home/kquick/.cabal --user --flags=-build-tests --flags=-no-cabal-dev --extra-include-dirs=/home/kquick/.nix-profile/include --extra-lib-dirs=/home/kquick/.nix-profile/lib --constraint=Cabal ==1.10.1.0 --constraint=HTTP ==4000.1.1 --constraint=base ==4.2.0.2 --constraint=bytestring ==0.9.1.9 --constraint=directory ==1.0.1.1 --constraint=filepath ==1.1.0.4 --constraint=mtl ==2.0.1.0 --constraint=network ==2.3.0.2 --constraint=pretty ==1.0.1.1 --constraint=process ==1.0.1.3 --constraint=tar ==0.3.1.0 --constraint=zlib ==0.5.3.1 cabal: Error: some packages failed to install: cabal-dev-0.7.4.1 failed during the configure step. The exception was: ExitFailure 11 $ -- -KQ