--- a/sys-devel/llvm/llvm-3.2.ebuild	
+++ a/sys-devel/llvm/llvm-3.2.ebuild	
@@ -151,7 +151,7 @@ src_compile() {
 	emake VERBOSE=1 KEEP_SYMBOLS=1 REQUIRES_RTTI=1
 
 	if use doc; then
-		emake -C docs -f Makefile.sphinx man html
+		emake -j1 -C docs -f Makefile.sphinx man html
 	fi
 	#	emake -C docs -f Makefile.sphinx html