Index: head/x11-wm/river/Makefile
===================================================================
--- head/x11-wm/river/Makefile	(revision 555685)
+++ head/x11-wm/river/Makefile	(revision 555686)
@@ -1,54 +1,59 @@
 # $FreeBSD$
 
 PORTNAME=	river
 PORTVERSION=	s20201118
 CATEGORIES=	x11-wm
 
 MAINTAINER=	jbeich@FreeBSD.org
 COMMENT=	Dynamic tiling Wayland compositor
 
 LICENSE=	GPLv3+
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BUILD_DEPENDS=	wayland-protocols>0:graphics/wayland-protocols \
 		wlroots>=0.12.0:x11-toolkits/wlroots \
 		zig>=0.7.0:lang/zig
 LIB_DEPENDS=	libevdev.so:devel/libevdev \
 		libwayland-server.so:graphics/wayland \
 		libwlroots.so:x11-toolkits/wlroots \
 		libxkbcommon.so:x11/libxkbcommon
 
 USES=		pkgconfig
 USE_GITHUB=	yes
 GH_ACCOUNT=	ifreund
 GH_TAGNAME=	cbd4a28
 GH_TUPLE=	ifreund:zig-wayland:931b6f7:zig_wayland/deps/zig-wayland
 CONFIGURE_ARGS=	--prefix "${STAGEDIR}${PREFIX}" \
 		${WITH_DEBUG:U-Drelease-fast=true} \
 		--verbose
 NO_INSTALL=	yes # strip(1) breaks runtime
 PLIST_FILES=	bin/${PORTNAME} \
 		bin/${PORTNAME}ctl \
 		bin/${PORTNAME}tile
 
 OPTIONS_DEFINE=	MANPAGES X11
 OPTIONS_DEFAULT=MANPAGES X11
 
 MANPAGES_BUILD_DEPENDS=	scdoc:textproc/scdoc
 MANPAGES_CONFIGURE_ON=	-Dman-pages=true
 MANPAGES_CONFIGURE_OFF=	-Dman-pages=false
 MANPAGES_PLIST_FILES=	share/man/man1/${PORTNAME}.1.gz \
 			share/man/man1/${PORTNAME}ctl.1.gz \
 			share/man/man1/${PORTNAME}tile.1.gz \
 			share/man/man7/${PORTNAME}-layouts.7.gz
 
 X11_CONFIGURE_ON=	-Dxwayland=true
 X11_CONFIGURE_OFF=	-Dxwayland=false
 
+post-patch:
+# Respect PREFIX for system-wide config (a la sysconfdir in Meson)
+	@${REINPLACE_CMD} -e 's,/etc,${PREFIX}&,' \
+		${WRKSRC}/river/main.zig
+
 do-build:
 	@(cd ${WRKSRC} && ${MAKE_ENV} zig build ${CONFIGURE_ARGS})
 
 do-test:
 	@(cd ${WRKSRC} && ${TEST_ENV} zig build test ${CONFIGURE_ARGS})
 
 .include <bsd.port.mk>