Index: head/shells/ksh93/Makefile
===================================================================
--- head/shells/ksh93/Makefile	(revision 508704)
+++ head/shells/ksh93/Makefile	(revision 508705)
@@ -1,49 +1,53 @@
 # $FreeBSD$
 
 PORTNAME=	ksh93
 DISTVERSION=	2020.0.0-alpha1
 PORTEPOCH=	1
 PORTREVISION=	3
 CATEGORIES=	shells
 
 MAINTAINER=	cy@freebsd.org
 COMMENT=	AT&T KornShell 93
 
 LICENSE=	EPL
 
 USES=		compiler:c11 meson ninja python:build
 
+.if ${USE_GCC} == "9"
+BROKEN=		GCC 9.1 changes the output of `gcc -E` which breaks the conf.sh script, fixed in shells/ksh93-devel
+.endif
+
 USE_GITHUB=	yes
 GH_ACCOUNT=	att
 GH_PROJECT=	ast
 GH_TAGNAME=	${HASH}
 
 KSH_CONFLICTS=		pdksh-*
 KSH93_CONFLICTS=	ksh93-devel-* ast-ksh-*
 
 MESON_BUILD_DIR=	build
 
 OPTIONS_DEFAULT=	KSH93
 OPTIONS_SINGLE=		BIN_KSH
 OPTIONS_SINGLE_BIN_KSH=	KSH KSH93
 KSH_DESC=		Install to ${PREFIX}/bin/ksh
 KSH93_DESC=		Install to ${PREFIX}/bin/ksh93
 
 KSH93_EXTRA_PATCHES=	${FILESDIR}/extra-patch-install-as-ksh93
 
 KSH_PLIST_SUB=		93=""
 KSH93_PLIST_SUB=	93="93"
 
 .include <bsd.port.options.mk>
 
 post-patch:
 	@${REINPLACE_CMD} -e '/for name in/ s|python.*|${PYTHON_CMD}|g' ${WRKSRC}/scripts/python.sh
 	@${REINPLACE_CMD} -e 's|SF_FLAGS|SFIO_FLAGS|g' ${WRKSRC}/src/lib/libast/include/sfio*.h ${WRKSRC}/src/lib/libast/sfio/*.c
 .if ${PORT_OPTIONS:MKSH93}
 	@${MV} ${WRKSRC}/src/cmd/ksh93/ksh.1 ${WRKSRC}/src/cmd/ksh93/ksh93.1
 .endif
 .if ${PORT_OPTIONS:MKSH}
 	@# Keep portlint happy
 .endif
 
 .include <bsd.port.mk>