cabal

[Christian Maeder]

Duncan Coutts wrote:
> The basic problem here is that the version number of the network package
> has not been bumped.

see below

> You probably installed from a ghc bindist that has
> network-2.2.0.0 already,

Yes, you're right, and I didn't notice that, because I relied on cabal
install.

> however it's not the same as network-2.2.0.0
> from hackage. The pre-installed one is built against base-4, so when
> cabal-install tries to rebuild it then it tries to build it against base
> 4 which does not work because the one on hackage has not been updated.

So network-2.2.0.0 should be linked against base-3 within the binary
dist of ghc-6.10 (or not shipped with ghc-6.10 at all.

In fact it worked after I've unregistered my global network-2.2.0.0,
first! (but I didn't get much further, see below)

> Normally cabal-install would use base-3 but in this case it's picking 4
> because the version that is already installed used 4 so the assumption
> is that since the same version is already installed then it does indeed
> work with base 4. Of course that's not true here because the package has
> changed without the version being bumped.

Or cabal-install should be smarter (or less smart).

> Indeed the only reason it's trying to rebuild it at all is because the
> installed version has different deps from the available version, again
> due to the fact that it changed without changing version number.
> 
> So the solution is for the updated network package to have its version
> bumped and for it to be released.

So why is the version of network not bumped, yet? The maintainer is
libraries at haskell.org. Would it interfere with ghc-6.8?

Cheers and thanks for your explanation
Christian

P.S. for hxt and Shellac-editline the sources need to be changed for
ghc-6.10:

[ 49 of 112] Compiling Text.XML.HXT.RelaxNG.DataTypeLibUtils (
src/Text/XML/HXT/RelaxNG/DataTypeLibUtils.hs,
dist/build/Text/XML/HXT/RelaxNG/DataTypeLibUtils.o )

src/Text/XML/HXT/RelaxNG/DataTypeLibUtils.hs:67:7:
    `>>>' is not a (visible) method of class `Arrow'
cabal: Error: some packages failed to install:
hxt-8.1.0 failed during the building phase. The exception was:
exit: ExitFailure 1

Building Shellac-editline-0.9...
[1 of 1] Compiling System.Console.Shell.Backend.Editline (
src/System/Console/Shell/Backend/Editline.hs,
dist/build/System/Console/Shell/Backend/Editline.o )

src/System/Console/Shell/Backend/Editline.hs:48:45:
    Couldn't match expected type `()' against inferred type `Bool'
      Expected type: IO ()
      Inferred type: IO Bool
    In the expression: EL.readHistory
    In the `readHistory' field of a record
cabal: Error: some packages failed to install:
Shellac-editline-0.9 failed during the building phase. The exception was:
exit: ExitFailure 1