diff -ruN cad/stepcode.orig/Makefile cad/stepcode/Makefile
--- cad/stepcode.orig/Makefile	2017-08-26 17:39:24.648038000 +0200
+++ cad/stepcode/Makefile	2017-08-26 17:38:08.308823000 +0200
@@ -4,7 +4,7 @@
 PORTNAME=	stepcode
 PORTVERSION=	0.8
 DISTVERSIONPREFIX=	v
-PORTREVISION=	2
+PORTREVISION=	3
 CATEGORIES=	cad
 
 MAINTAINER=	fernando.apesteguia@gmail.com
@@ -23,6 +23,23 @@
 CMAKE_ARGS+=	-DSC_INSTALL_PREFIX=${PREFIX} \
 		-DSC_BUILD_TYPE=Release
 
+.include <bsd.port.pre.mk>
+
+# There's a regression in clang 5.0 thak makes the compiler
+# take ages to compile this port and report the process
+# as run-away.
+# This should be reverted once this is fixed upstream and we
+# have imported those changes.
+# In the meantime, fallback to clang 3.8
+#
+# For details, see:  https://lists.freebsd.org/pipermail/freebsd-hackers/2017-August/051361.html
+
+.if ${ARCH} == "i386" && ${COMPILER_TYPE} == clang && ${COMPILER_VERSION} == 50
+CC=	"clang38"
+CXX=	"clang++38"
+CPP=	"clang-cpp38"
+.endif
+
 MANDIRS=	${PREFIX}/share/man
 
 post-install:
@@ -30,4 +47,4 @@
 	@(cd ${STAGEDIR}${PREFIX} ; \
 		${FIND} include \( -type f -or -type l \) | ${SORT} >> ${TMPPLIST})
 
-.include <bsd.port.mk>
+.include <bsd.port.post.mk>