Build fail on MacOSX 1.4.5

Hello,

been trying tobuild ghc from scratch (I'd like to fiddle with its code).
I work on a PowerBook Mac under version 1.4.5 of MacOSX and
the compile failed on the 1.4.2 sources from the haskell.org/ghc
site. Strangely, this seemed also to be a bug on MacOSX 1.3.9
and a bug tracking report told me it was fixed. So what happened here?
Can anybody help me out? Please reply to this message, since I am not
a member of this group (yet).

The output of the compiler is this:
...lots of stuf omitted...
------------------------------------------------------------------------
/usr/local/bin/ghc -H16m -O  -istage1/utils  -istage1/basicTypes  - 
istage1/types  -istage1/hsSyn  -istage1/prelude  -istage1/rename  - 
istage1/typecheck  -istage1/deSugar  -istage1/coreSyn  -istage1/ 
specialise  -istage1/simplCore  -istage1/stranal  -istage1/stgSyn  - 
istage1/simplStg  -istage1/codeGen  -istage1/main  -istage1/ 
profiling  -istage1/parser  -istage1/cprAnalysis  -istage1/compMan  - 
istage1/ndpFlatten  -istage1/iface  -istage1/cmm  -istage1/nativeGen   
-istage1/ghci -Istage1 -DGHCI -package template-haskell -package  
readline -DUSE_READLINE -cpp -fglasgow-exts -fno-generics -Rghc- 
timing -I. -IcodeGen -InativeGen -Iparser -package unix -ignore- 
package lang -recomp -Rghc-timing  -H16M '-#include "hschooks.h"' - 
i../lib/compat -ignore-package Cabal    -c utils/PrimPacked.lhs -o  
stage1/utils/PrimPacked.o  -ohi stage1/utils/PrimPacked.hi

utils/PrimPacked.lhs:250:0:
    Warning: foreign declaration uses deprecated non-standard syntax

utils/PrimPacked.lhs:254:0:
    Warning: foreign declaration uses deprecated non-standard syntax

utils/PrimPacked.lhs:257:0:
    Warning: foreign declaration uses deprecated non-standard syntax

utils/PrimPacked.lhs:260:0:
    Warning: foreign declaration uses deprecated non-standard syntax

utils/PrimPacked.lhs:263:0:
    Warning: foreign declaration uses deprecated non-standard syntax
In file included from /tmp/ghc29849.hc:5:
/usr/local/lib/ghc-6.4.1/include/HsUnix.h: In function  
'__hsunix_rtldNext':
/usr/local/lib/ghc-6.4.1/include/HsUnix.h:103: error: 'RTLD_NEXT'  
undeclared (first use in this function)
/usr/local/lib/ghc-6.4.1/include/HsUnix.h:103: error: (Each  
undeclared identifier is reported only once
/usr/local/lib/ghc-6.4.1/include/HsUnix.h:103: error: for each  
function it appears in.)
/usr/local/lib/ghc-6.4.1/include/HsUnix.h: In function  
'__hsunix_rtldDefault':
/usr/local/lib/ghc-6.4.1/include/HsUnix.h:107: error: 'RTLD_DEFAULT'  
undeclared (first use in this function)
<<ghc: 49082080 bytes, 10 GCs, 1539742/2981452 avg/max bytes  
residency (2 samples), 17M in use, 0.13 INIT (0.00 elapsed), 0.54 MUT  
(1.13 elapsed), 0.25 GC (0.36 elapsed) :ghc>>
make[2]: *** [stage1/utils/PrimPacked.o] Error 1
make[1]: *** [all] Error 1
make: *** [build] Error 1

cheers,
Jur(riaan Hage)