Build failure of 7.8RC1 on OSX Mountain Lion

Possibly I did something wrong (certainly when I tried to build something very close to RC1 at Austin's request it worked fine), but now I am getting In file included from rts/sm/Evac.c:21:0: rts/sm/GCTDecl.h:71:0: error: thread-local storage not supported for this target (Host compiler: ghc 7.6.3, no mk/build.mk, standard ./configure --prefix=.., make) Any ideas? -Edsko