Working with GHC HEAD

[Simon Marlow]

On 26/07/2009 21:09, Antoine Latter wrote:
> Folks,
>
> I was trying to see what GHC head was like, but I've run into a few
> snags compiling packages.
>
> My existing binary for cabal-install can install quite a few packages,
> but then starts giving me strange errors eventually:
>
>>>>
> $ cabal --version
> cabal-install version 0.6.2
> using version 1.6.0.1 of the Cabal library
>
> $ ghc --version
> The Glorious Glasgow Haskell Compilation System, version 6.11.20090724
>
> $ cabal install zlib
> Resolving dependencies...
> Configuring zlib-0.5.2.0...
> ghc-stage2: /home/alatter/.ghc/x86_64-linux-6.11.20090724/package.conf:6:163:
>      parse error on input `Nothing'
> cabal: Error: some packages failed to install:
> zlib-0.5.2.0 failed during the configure step. The exception was:
> exit: ExitFailure 1
> <<<
>
> If I then do:
>
>>>>
> $ mv /home/alatter/.ghc/x86_64-linux-6.11.20090724/package.conf
> /home/alatter/.ghc/x86_64-linux-6.11.20090724/package.conf.back
>
> $ cabal install zlib
> <<<
>
> Everything works great.
>
> After looking at the package.conf being complained about, the last
> line looks like so:
>
>>>>
> InstalledPackageInfo {package = PackageIdentifier {pkgName =
> PackageName "cpphs", pkgVersion = Version {versionBranch = [1,7],
> versionTags = []}}, license = LGPL Nothing, copyright = "2004-8,
> Malcolm Wallace", maintainer = "Malcolm Wallace
> <Malcolm.Wallace at cs.york.ac.uk>", author = ...
> <<<
>
> Not the license field of the package info - we have "license = LGPL
> Nothing, copright ...".
>
> I thought that maybe since GHC head ships with the new dev version of
> Cabal, I need the dev version of cabal-install to properly install
> packages. However cabal-install (and most of the things I want to test
> out) require the 'network' package, which doesn't build against GHC
> head (System.Posix.Internals doesn't exist, and the functionality that
> 'network' uses from there now lives in GHC.IO.* and is much changed).
>
> So a few things:
>
> - Should I expect the stable version of cabal-install built against
> GHC 6.10 to work for head? Are the errors I'm getting expected?

Yes, you'll need a new cabal-install built against the version of Cabal 
that comes with GHC HEAD.

> - Does anyone have a version of 'network' which builds against GHC
> head? I could bludgeon in the new GHC.IO.FD.FD type myself, but I'd
> thought I'd ask around first.

Not that I know of.  This is something that needs to be done for the 
first platform release after GHC 6.12.1, but preferably earlier in case 
there are any changes we need to make in base.

Cheers,
	Simon