Index: head/audio/kwave/Makefile
===================================================================
--- head/audio/kwave/Makefile	(revision 467244)
+++ head/audio/kwave/Makefile	(revision 467245)
@@ -1,37 +1,47 @@
 # $FreeBSD$
 
 PORTNAME=	kwave
 DISTVERSION=	${KDE_APPLICATIONS_VERSION}
 CATEGORIES=	audio kde kde-applications
 
 MAINTAINER=	kde@FreeBSD.org
 COMMENT=	Sound editor for KDE
 
 BUILD_DEPENDS=	convert:graphics/ImageMagick
 LIB_DEPENDS=	libaudiofile.so:audio/libaudiofile \
 		libFLAC.so:audio/flac \
 		libfftw3.so:math/fftw3 \
 		libid3.so:audio/id3lib \
 		libmad.so:audio/libmad \
 		libogg.so:audio/libogg \
 		libopus.so:audio/opus \
 		libsamplerate.so:audio/libsamplerate \
 		libvorbisenc.so:audio/libvorbis
 
 USES=		cmake:outsource desktop-file-utils gettext kde:5 \
 		localbase:ldflags pkgconfig tar:xz
 USE_KDE=	archive auth bookmarks codecs completion config configwidgets \
 		coreaddons crash dbusaddons ecm i18n iconthemes itemviews \
 		jobwidgets kio service solid sonnet textwidgets widgetsaddons \
 		xmlgui
 USE_QT5=	concurrent core dbus gui multimedia network widgets xml \
 		buildtools_build qmake_build
 
 OPTIONS_GROUP=			AUDIOPLUGIN
 OPTIONS_GROUP_AUDIOPLUGIN=	ALSA PULSEAUDIO
 ALSA_CMAKE_BOOL=		WITH_ALSA
 ALSA_LIB_DEPENDS=		libasound.so:audio/alsa-lib
 PULSEAUDIO_CMAKE_BOOL=		WITH_PULSEAUDIO
 PULSEAUDIO_LIB_DEPENDS=		libpulse.so:audio/pulseaudio
 
-.include <bsd.port.mk>
+.include <bsd.port.pre.mk>
+
+.  if ${OPSYS} == FreeBSD && ${OSVERSION} >= 1100000 && ${OSVERSION} < 1101505
+BUILD_DEPENDS+=		llvm50>=0:devel/llvm50
+# Build is broken on 11.x as clang is not new enough.
+# Workaround by manually setting CC to clang50.
+CC=		${LOCALBASE}/bin/clang50
+CXX=		${LOCALBASE}/bin/clang++50
+.  endif
+
+.include <bsd.port.post.mk>