Index: head/devel/simgear/Makefile
===================================================================
--- head/devel/simgear/Makefile	(revision 494554)
+++ head/devel/simgear/Makefile	(revision 494555)
@@ -1,30 +1,36 @@
 # $FreeBSD$
 
 PORTNAME=	simgear
 PORTVERSION=	2018.3.2
 CATEGORIES=	devel games
 MASTER_SITES=	SF/flightgear/release-${PORTVERSION:R}
 
 MAINTAINER=	martymac@FreeBSD.org
 COMMENT=	Toolkit for 3D games and simulations
 
 LICENSE=	GPLv2
 
 BUILD_DEPENDS=	${LOCALBASE}/lib/libplibsl.a:x11-toolkits/plib
 RUN_DEPENDS=	${LOCALBASE}/lib/libplibsl.a:x11-toolkits/plib
 LIB_DEPENDS=	libboost_thread.so:devel/boost-libs \
 		libosg.so:graphics/osg
 
 USES=		alias cmake compiler:c++11-lib cpe gl jpeg openal:al,alut \
 		tar:bzip2
 USE_XORG=	ice sm x11 xext xi xmu xt
 USE_GL=		gl glu glut
 
 LDFLAGS_mips=	-losgDB
 LDFLAGS_mips64=	-losgDB
 LDFLAGS_powerpc64=	-losgDB
 LDFLAGS_powerpc=	-losgDB
 LDFLAGS_powerpcspe=	-losgDB
 LDFLAGS_sparc64=	-losgDB
 
+post-patch:
+# Avoid conflict with C++20 <version> by adding .txt suffix
+	@${MV} ${WRKSRC}/version ${WRKSRC}/version.txt
+	@${REINPLACE_CMD} -Ei .c++20 '/file|set_prop/s/version[[:>:]]/&.txt/' \
+		${WRKSRC}/CMakeLists.txt
+
 .include <bsd.port.mk>