From 32e1652c9ca826d602e783ec96cba192705a8085 Mon Sep 17 00:00:00 2001
From: Valentin Rothberg <rothberg@redhat.com>
Date: Thu, 1 Aug 2019 13:20:14 +0200
Subject: [PATCH] go build: use `-mod=vendor` for go >= 1.11.x

Go 1.13.x isn't sensitive to the `GO111MODULE` environment variable
causing `make binary-local` to not use the vendored sources in
`./vendor`.  Force builds of module-supporting go versions to use the
vendored sources by setting `-mod=vendor`.

Verified in a `fedora:rawhide` container.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
---
 Makefile | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 64450cba..568956ea 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,5 @@
 .PHONY: all binary build-container docs docs-in-container build-local clean install install-binary install-completions shell test-integration .install.vndr vendor
 
-export GO111MODULE=off
-
 ifeq ($(shell uname),Darwin)
 PREFIX ?= ${DESTDIR}/usr/local
 DARWIN_BUILD_TAG=containers_image_ostree_stub
@@ -26,6 +24,12 @@ GO ?= go
 CONTAINER_RUNTIME := $(shell command -v podman 2> /dev/null || echo docker)
 GOMD2MAN ?= $(shell command -v go-md2man || echo '$(GOBIN)/go-md2man')
 
+GO_BUILD=$(GO) build
+# Go module support: set `-mod=vendor` to use the vendored sources
+ifeq ($(shell go help mod >/dev/null 2>&1 && echo true), true)
+  GO_BUILD=GO111MODULE=on $(GO) build -mod=vendor
+endif
+
 ifeq ($(DEBUG), 1)
   override GOGCFLAGS += -N -l
 endif
@@ -95,10 +99,10 @@ binary-static: cmd/skopeo
 
 # Build w/o using containers
 binary-local:
-	$(GPGME_ENV) $(GO) build ${GO_DYN_FLAGS} -ldflags "-X main.gitCommit=${GIT_COMMIT}" -gcflags "$(GOGCFLAGS)" -tags "$(BUILDTAGS)" -o skopeo ./cmd/skopeo
+	$(GPGME_ENV) $(GO_BUILD) ${GO_DYN_FLAGS} -ldflags "-X main.gitCommit=${GIT_COMMIT}" -gcflags "$(GOGCFLAGS)" -tags "$(BUILDTAGS)" -o skopeo ./cmd/skopeo
 
 binary-local-static:
-	$(GPGME_ENV) $(GO) build -ldflags "-extldflags \"-static\" -X main.gitCommit=${GIT_COMMIT}" -gcflags "$(GOGCFLAGS)" -tags "$(BUILDTAGS)" -o skopeo ./cmd/skopeo
+	$(GPGME_ENV) $(GO_BUILD) -ldflags "-extldflags \"-static\" -X main.gitCommit=${GIT_COMMIT}" -gcflags "$(GOGCFLAGS)" -tags "$(BUILDTAGS)" -o skopeo ./cmd/skopeo
 
 build-container:
 	${CONTAINER_RUNTIME} build ${BUILD_ARGS} -t "$(IMAGE)" .