Building from a clean checkout of HEAD (from today) I get: "inplace/bin/ghc-stage2" -H32m -O -package-name dph-seq-0.4.0 -hide-all-packages -i -ilibraries/dph/dph-seq/../dph-common -ilibraries/dph/dph-seq/dist-install/build -ilibraries/dph/dph-seq/dist-install/build/autogen -Ilibraries/dph/dph-seq/dist-install/build -Ilibraries/dph/dph-seq/dist-install/build/autogen -Ilibraries/dph/dph-seq/. -optP-include -optPlibraries/dph/dph-seq/dist-install/build/autogen/cabal_macros.h -package array-0.3.0.0 -package base-4.3.0.0 -package dph-base-0.4.0 -package dph-prim-seq-0.4.0 -package ghc-6.13.20100720 -package ghc-prim-0.2.0.0 -package random-1.0.0.2 -package template-haskell-2.4.0.0 -Odph -funbox-strict-fields -fcpr-off -fdph-this -package-name dph-seq -XTypeFamilies -XGADTs -XRankNTypes -XBangPatterns -XMagicHash -XUnboxedTuples -XTypeOperators -no-user-package-conf -rtsopts -O2 -XGenerics -fno-warn-deprecated-flags -odir libraries/dph/dph-seq/dist-install/build -hidir libraries/dph/dph-seq/dist-install/build -stubdir libraries/dph/dph-seq/dist-install/build -hisuf hi -osuf o -hcsuf hc -c libraries/dph/dph-seq/../dph-common/Data/Array/Parallel/Lifted/PArray.hs -o libraries/dph/dph-seq/dist-install/build/Data/Array/Parallel/Lifted/PArray.o Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package array-0.3.0.0 ... linking ... done. Loading package containers-0.3.0.0 ... linking ... done. Loading package filepath-1.2.0.0 ... linking ... done. Loading package old-locale-1.0.0.2 ... linking ... done. Loading package old-time-1.0.0.5 ... linking ... done. Loading package unix-2.4.0.1 ... linking ... done. Loading package directory-1.0.1.2 ... linking ... done. Loading package pretty-1.0.1.1 ... linking ... done. Loading package process-1.0.1.3 ... linking ... done. ghc-stage2: internal error: Invalid Mach-O file:Address out of bounds while relocating object file (GHC version 6.13.20100720 for i386_apple_darwin) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug make[1]: *** [libraries/dph/dph-seq/dist-install/build/Data/Array/Parallel/Lifted/PArray.o] Abort trap make: *** [all] Error 2 P.S. I'm running OS X 10.5.8 on a Intel Core 2 Duo Mac Book Pro.