if baseDist == DefaultVariant {
		baseDist = PrimaryVariant
	}
	m := map[string]string{
		// Base version defines the tag of the base image to use. Typically, set in the Makefile and not overridden.
		"BASE_VERSION": args.BaseVersion,
		// Registry where the base image is stored
		"ISTIO_BASE_REGISTRY": args.BaseImageRegistry,
		// Base distribution picks which variant to build
		"BASE_DISTRIBUTION": baseDist,

		SupportsEmulation: qemu,
	}
}

var (
	globalArgs = DefaultArgs()
	version    = false
)

var baseVersionRegexp = regexp.MustCompile(`BASE_VERSION \?= (.*)`)

func fetchBaseVersion() string {
	if b, f := os.LookupEnv("BASE_VERSION"); f {
		return b
	}
	b, err := os.ReadFile(filepath.Join(testenv.IstioSrc, "Makefile.core.mk"))
	if err != nil {
		log.Fatalf("failed to read file: %v", err)

$(error VERSION not detected. Make sure it's stored in the VERSION file or defined in VERSION variable)
endif
VERSION := $(VERSION_FROM_FILE)-dev
endif

export VERSION

# Base version of Istio image to use
BASE_VERSION ?= master-2024-06-02T19-03-25
ISTIO_BASE_REGISTRY ?= gcr.io/istio-release

export GO111MODULE ?= on
export GOPROXY ?= https://proxy.golang.org
export GOSUMDB ?= sum.golang.org