if err != nil {
		return nil, err
	}
	env := []string{
		pathEnvName() + "=" + testBin + string(filepath.ListSeparator) + os.Getenv(pathEnvName()),
		homeEnvName() + "=/no-home",
		"CCACHE_DISABLE=1", // ccache breaks with non-existent HOME
		"GOARCH=" + runtime.GOARCH,
		"TESTGO_GOHOSTARCH=" + goHostArch,
		"GOCACHE=" + testGOCACHE,
		"GOCOVERDIR=" + os.Getenv("GOCOVERDIR"),