Better fix: just use the pregenerated Lexer and Parser.

devel/haddock/Makefile

@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.38 2012/09/03 17:01:54 kili Exp $
+# $OpenBSD: Makefile,v 1.39 2012/09/03 17:35:25 kili Exp $
 
 COMMENT-main =	documentation-generation tool for Haskell libraries
 COMMENT-lib =	haddock library
@@ -36,9 +36,7 @@ WANTLIB-lib =
 WANTLIB-main =		${WANTLIB} \
 			c gmp m pthread util
 
-BUILD_DEPENDS +=	devel/alex \
-			devel/happy \
-			devel/hs-ghc-paths \
+BUILD_DEPENDS +=	devel/hs-ghc-paths \
 			lang/ghc,-doc \
 			textproc/docbook \
 			textproc/docbook-xsl \
@@ -56,6 +54,7 @@ WRKCONF =		${AUTOCONF_DIR}
 
 post-extract:
 	mv ${WRKDIR}/lang/ghc/ghc-${MODGHC_VER}/utils/haddock ${WRKSRC}
+	rm -f ${WRKSRC}/src/Haddock/*.source
 
 post-build:
 	@cd ${WRKBUILD}/doc && exec ${SETENV} ${MAKE_ENV} ${MAKE_PROGRAM} html

devel/haddock/patches/patch-haddock_cabal

@@ -0,0 +1,25 @@
+$OpenBSD: patch-haddock_cabal,v 1.3 2012/09/03 17:35:25 kili Exp $
+--- haddock.cabal.orig	Wed Jun  6 19:10:26 2012
++++ haddock.cabal	Mon Sep  3 19:16:37 2012
+@@ -78,10 +78,6 @@ flag test
+ 
+ executable haddock
+   default-language:     Haskell2010
+-  -- In a GHC tree - in particular, in a source tarball - we don't
+-  -- require alex or happy
+-  if !flag(in-ghc-tree)
+-    build-tools: alex >= 2.3, happy >= 1.18
+   build-depends:
+     base >= 4.3 && < 4.6,
+     filepath,
+@@ -140,10 +136,6 @@ executable haddock
+    
+ library
+   default-language:     Haskell2010
+-  -- In a GHC tree - in particular, in a source tarball - we don't
+-  -- require alex or happy
+-  if !flag(in-ghc-tree)
+-    build-tools: alex >= 2.3, happy >= 1.18
+   build-depends:
+     base >= 4.3 && < 4.6,
+     filepath,