How to use this toolchain to build ghc software with cabal-install

[kencu]

To use these tools with an older MacOS system like 10.6.8, you will need to supplement the older MacOSX SDK with newer features using MacPorts and the macports-legacy-support library.

cabal will accept direction on adding extra include directories to the build, and also will accept additional linked in libraries. Linking in the legacy-support library statically seems most appropriate.

To add these to all cabal builds, edit the config file at:

~/.cabal/config

I modified these items (NB: indentation is important):

program-default-options
  -- alex-options:
  -- ar-options:
  -- c2hs-options:
  -- cpphs-options:
  -- doctest-options:
  gcc-options: -I/opt/local/include/LegacySupport -Wl,/opt/local/lib/libMacportsLegacySupport.a
  -- ghc-options:
  -- ghc-pkg-options:
  -- ghcjs-options:
  -- ghcjs-pkg-options:
  -- greencard-options:
  -- haddock-options:
  -- happy-options:
  -- haskell-suite-options:
  -- haskell-suite-pkg-options:
  -- hmake-options:
  -- hpc-options:
  -- hsc2hs-options:
  -- hscolour-options:
  -- jhc-options:
  ld-options: /opt/local/lib/libMacportsLegacySupport.a
  -- pkg-config-options:
  -- runghc-options:
  -- strip-options:
  -- tar-options:
  -- uhc-options:

and after doing that, when building ghc software using cabal, legacy-support is used and linked in automatically.

This takes care of most (but not always all) SDK issues.

Of course you will need to have a reasonable ghc version on your PATH or ghc won't be found during the build. You also need to have the PATH to MacPorts newer toolchain parts available (usually /opt/local/bin).