ghc 6.0.1 and Mac OS X 10.2.6 build

[Wolfgang Thaller]

> I should note that I've done
> the build without Wolfgang's HaskellSupportFramework, by setting the 
> include
> and library paths in build.mk. This is more compatible with the 
> automated packing
> scheme of DarwinPorts.

Of course. The HaskellSupport.framework isn't necessary when the user 
already has DarwinPorts installed; be sure to note somewhere that 
GHC-compiled programs will require gmp and dlcompat.

> by setting the include
> and library paths in build.mk.

The "official" way to disable the HaskellSupport.framework is to modify 
configure.in (yes, I should really add a --configure option for that):

Lines 978 to 991 read:
dnl ** (Mac OS X only: check for HaskellSupport.framework)
HaveFrameworkHaskellSupport=NO
if test $HostPlatform = "powerpc-apple-darwin"; then
  AC_MSG_CHECKING([for HaskellSupport.framework])
  save_libs="$LIBS"
  LIBS="-framework HaskellSupport"
  AC_TRY_LINK_FUNC(__gmpz_fdiv_qr, HaveFrameworkHaskellSupport=YES,)
  if test $HaveFrameworkHaskellSupport = YES; then
   AC_DEFINE(HAVE_FRAMEWORK_HASKELLSUPPORT)
  fi;
  LIBS="$save_libs"
  AC_MSG_RESULT([$HaveFrameworkHaskellSupport])
fi;
AC_SUBST(HaveFrameworkHaskellSupport)

Change that to just:
HaveFrameworkHaskellSupport=NO
AC_SUBST(HaveFrameworkHaskellSupport)

Then rerun autoconf and ./configure.

> The error message comes from ghc/rts/Linker.c. Apparently dlsym 
> couldn't
> find the symbol _free from libSystem.

Which is entirely strange. I see no reason why that could possibly 
happen.

> I suspect that doing things this way I have to link HSbase_cbits.o 
> (and its siblings)
> with -lSystem, Is that correct, or is this a different problem?

The ghci executable is already linked with -lSystem, otherwise it 
wouldn't work at all. And Linker.c calls dlsym on the program handle, 
which means that it just "has to" find _free.
What version of dlcompat are you using? dlcompat's dlsym should just 
call NSIsSymbolNameDefined and NSLookupAndBindSymbol when dlsym is 
called with the program handle.

Cheers,

Wolfgang