// and returns the go version and toolchain lines from the file.
// The toolchain line overrides the version line
func modGoToolchain() (file, goVers, toolchain string) {
	wd := base.UncachedCwd()
	file = modload.FindGoWork(wd)
	// $GOWORK can be set to a file that does not yet exist, if we are running 'go work init'.
	// Do not try to load the file in that case
	if _, err := os.Stat(file); err != nil {