Index: net-mgmt/alertmanager/Makefile
===================================================================
--- net-mgmt/alertmanager/Makefile	(revision 505531)
+++ net-mgmt/alertmanager/Makefile	(working copy)
@@ -12,23 +12,18 @@
 LICENSE=	APACHE20
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
-USES=		go gmake
+USES=		go:modules gmake
 USE_GITHUB=	yes
 GH_ACCOUNT=	prometheus
 USE_RC_SUBR=	alertmanager
 
-GO_PKGNAME=	github.com/prometheus/${PORTNAME}
+GO_TARGET=	./cmd/alertmanager \
+		./cmd/amtool
 
 USERS=		alertmanager
 GROUPS=		alertmanager
 
-do-build:
-	@cd ${GO_WRKSRC}/cmd/alertmanager && ${SETENV} ${MAKE_ENV} ${GO_ENV} go install
-	@cd ${GO_WRKSRC}/cmd/amtool && ${SETENV} ${MAKE_ENV} ${GO_ENV} go install
-
-do-install:
-	${INSTALL_PROGRAM} ${GO_WRKDIR_BIN}/alertmanager ${STAGEDIR}${PREFIX}/bin
-	${INSTALL_PROGRAM} ${GO_WRKDIR_BIN}/amtool ${STAGEDIR}${PREFIX}/bin
+post-install:
 	@${MKDIR} ${STAGEDIR}${PREFIX}/etc/alertmanager
 	${INSTALL_DATA} ${WRKSRC}/doc/examples/simple.yml ${STAGEDIR}${PREFIX}/etc/alertmanager/alertmanager.yml.sample