From d9cbdede414d2e37b5ae0b5297026b01f41d8b53 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Budai?= <obudai@redhat.com>
Date: Wed, 22 Apr 2020 14:40:42 +0200
Subject: [PATCH] tools/prepare-source: use a well-defined go version

go mod works differently in go 1.12 and go 1.13. When someone uses the
prepare-source tool with go >= 1.13, the ci complains because it uses
go 1.12. This commit changes the script to use a well-defined go version.
---
 tools/prepare-source.sh | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/tools/prepare-source.sh b/tools/prepare-source.sh
index f77218b57..b7a8c1550 100755
--- a/tools/prepare-source.sh
+++ b/tools/prepare-source.sh
@@ -2,6 +2,15 @@
 
 set -eux
 
-go fmt ./...
-go mod tidy
-go mod vendor
+GO_VERSION=1.12.17
+GO_BINARY=$(go env GOPATH)/bin/go$GO_VERSION
+
+# this is the official way to get a different version of golang
+# see https://golang.org/doc/install#extra_versions
+go get golang.org/dl/go$GO_VERSION
+$GO_BINARY download
+
+# prepare the sources
+$GO_BINARY fmt ./...
+$GO_BINARY mod tidy
+$GO_BINARY mod vendor