testing/docker: install tools in GOPATH mode
@@ -19,7 +19,8 @@ set -ex
apt-get update && apt-get install -y imagemagick graphviz
rm -rf /var/lib/apt/lists/*
-go get github.com/GoogleCloudPlatform/golang-samples/testing/gimmeproj github.com/jstemmer/go-junit-report
+# Install in GOPATH mode since Go 1.11 doesn't let you use go get without a go.mod.
+GO111MODULE=off go get github.com/GoogleCloudPlatform/golang-samples/testing/gimmeproj github.com/jstemmer/go-junit-report
# Get the SDK tar and untar it.
cd /tmp
