./configure --with-gcc=clang # the with gcc bit isnt needed, but making it clearly pick up clang is the point
error: unknown warning option '-Werror=unused-but-set-variable'; did you mean '-Werror=unused-const-variable'?
[-Werror,-Wunknown-warning-option]
which makes me think that the clang warning flags have changed in that release (which corresponds with clang Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)). SO maybe clang 3.5 / 3.6 will also fail when used in validate builds?
s/hpc/dist-boot/build/autogen/cabal_macros.h libraries/hpc/./Trace/Hpc/Reflect.hsc -o libraries/hpc/dist-boot/build/Trace/Hpc/Reflect.hs
error: unknown warning option '-Werror=unused-but-set-variable'; did you mean '-Werror=unused-const-variable'?
[-Werror,-Wunknown-warning-option]
compiling compiler/stage1/build/Fingerprint_hsc_make.c failed (exit code 1)
command was: clang -c compiler/stage1/build/Fingerprint_hsc_make.c -o compiler/stage1/build/Fingerprint_hsc_make.o -Werror -Wall -m64 -fno-stack-protector -m64 -Dx86_64_HOST_ARCH=1 -Ddarwin_HOST_OS=1 -D__GLASGOW_HASKELL__=708 -m64 -fno-stack-protector -error: unknown warning option '-Werror=unused-but-set-variable'; did you mean '-Werror=unused-const-variable'?
[-Werror,-Wunknown-warning-option]
Werror -Wall -Icompiler/. -Icompiler/parser -Icompiler/utils -Icompiler/stage1 -isystem/usr/local/lib/ghc-7.8.3/process-1.2.0.0/include -isystem/usr/local/lib/ghc-7.8.3/directory-1.2.1.0/include -isystem/usr/local/lib/ghc-7.8.3/unix-2.7.0.1/include -isystem/usr/local/lib/ghc-7.8.3/time-1.4.2/include -isystem/usr/loccalo/mlpiibl/ignhgc -l7i.b8r.a3r/ibeyst/ehsptc/dist-boot/build/Trace/Hpc/Reflect_hsc_make.c fring-0.10.4.0/include -isystemailed (exit c/usr/local/liode 1)
commab/ghc-7.8.3/band was: clanse-4.7.0.1/ing -c librariclude -isystees/hpc/dist-m/usr/localboot/build/T/lib/ghc-7.8race/Hpc/Ref.3/inlteecgte_rh-sgcm_pm-a0k.e5.1.0/include -isys.c -o libraries/hpc/dist-boott/bueiml/du/sTrr/acel/Hopcca/l/lib/ghc-7.8.3/include -Werror=unused-but-sReet-variabflel e-Wcnto_-hesrcr_omra=kien.loi n-eW e-rIrcoorm p-iWlaelrl/ s-tma6g4e 1-/fbnuoi-lsdt/aacukt-opgreont e-citnocrl u-dme6 4c o-mDpxi8l6e_r6/4s_tHaOgSeT1_/AbRuCiHl=d1/ a-uDtdoagrewni/nc_aHbOaSlT__mOaSc=r1o s-.Dh_ _-GIL/AUSsGeOrWs_/HcAaSrKtEeLrL/_D_e=s7k0t8o p-/mr6e4p o-Sfcnor-asttcahcekr-/pgrhoct-evcatloirf a-iWle/rirnoprl a-cWea/llli b-/Iilnicblrudaer/i
es/hpc/. -isystem/usr/local/lib/ghc-7.8.3/directory-1.2.1.0/include -isystem/usr/local/lib/ghc-7.8.3/unix-2.7.0.1/include -isystem/usr/local/lib/ghc-7.8.3/time-1.4.2/include -isystem/usr/local/lib/ghc-7.8.3/bytestring-0.10.4.0/include -isystem/usr/local/lib/ghc-7.8.3/base-4.7.0.1/include -isystem/usr/local/lib/ghc-7.8.3/integer-gmp-0.5.1.0/include -isystem/usr/local/lib/ghc-7.8.3/include -Werror=unused-but-set-variable -Wno-error=inline -Ilibraries/hpc/dist-boot/build/autogen -include libraries/hpc/dist-boot/build/amake[1]: *** [compiler/stage1/build/Fingerprint.hs] Error 1
make[1]: *** Waiting for unfinished jobs....
utogen/cabal_macros.h -I/Users/carter/Desktop/repoScratcher/ghc-valifail/inplace/lib/include/
make[1]: *** [libraries/hpc/dist-boot/build/Trace/Hpc/Reflect.hs] Error 1
make: *** [all] Error 2