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