> Take a look at the Cabal.cabal file, how this is solved, atm.

where is this, how can I take a look at it?

> The next release of Cabal (and the current HEAD) supports conditionals

I couldn't install head, but since I'm running 6.7, do I already have it?

hartthoma@linuxpt:~/installs/cabal-head/cabal>runghc Setup.lhs configure

Distribution/Simple/InstallDirs.hs:267:36:
Not in scope: `dropDrive'

hartthoma@linuxpt:~/installs/cabal-head/cabal>ls -l `which ghc`
lrwxrwxrwx 1 root root 31 2007-08-20 11:08 /usr/local/bin/ghc -> /usr/local/bin/ghc-6.7.20070816

hartthoma@linuxpt:~/installs/cabal-head/cabal>ghc-pkg list | grep -i cabal
Cabal-1.1.7

> Please also note that this might not be the > best way to use the new features; as I suggested in another thread, > simulating base-1.0 on systems with base-2.0 is probably best handled > with a base.cabal file that imports base-2.0, old-time, etc. and re- > exports all imported modules to get a "virtual" base-1.0.

I'm interested in seeing how this works, but I couldn't find that other thread.

Where is the documentation for the new functionality in cabal head, or do you just have to read the source code for now?

thanks, t

Thomas Schilling <nominolo@googlemail.com>

08/20/2007 01:37 PM

To	Thomas Hartman/ext/dbcom@DBAmericas
cc	haskell-cafe <haskell-cafe@haskell.org>
Subject	Re: [Haskell-cafe] is there a way to patch the build-depends line of a cabal file without breaking backwards compatibility?

On 20 aug 2007, at 18.37, Thomas Hartman wrote: > > cafe, is there a way to patch the build-depends line of a cabal > file without breaking backwards compatibility? > > I just patched HDBC head to compile under ghc 6.7. Unfortunately it > now won't compile in 6.6.1. > > is there a way for build-depends to detect which version of ghc > you're on? > > also I seem to recall that -fglasgow-exts was deprecated under 6.7. > is there a better way to beat back the error message below than this? > The next release of Cabal (and the current HEAD) supports conditionals to test for flags, os/arch, and implementation (+version). Note that the problem isn't the GHC version, but the new base version, in which the old base was split up into smaller packages, so we have something roughly like: base-1.0 = base-2.0 + bytestring + old-time + mtl. Take a look at the Cabal.cabal file, how this is solved, atm. Please also note that this might not be the best way to use the new features; as I suggested in another thread, simulating base-1.0 on systems with base-2.0 is probably best handled with a base.cabal file that imports base-2.0, old-time, etc. and re- exports all imported modules to get a "virtual" base-1.0. / Thomas

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