if err != nil {
		log.Fatal(err)
	}
	const goosPrefix = `var knownOS = map[string]bool{`
	inGOOS := false
	for _, line := range strings.Split(string(data), "\n") {
		if strings.HasPrefix(line, goosPrefix) {
			inGOOS = true
		} else if inGOOS && strings.HasPrefix(line, "}") {
			break
		} else if inGOOS {
			goos := strings.Fields(line)[0]
			goos = strings.TrimPrefix(goos, `"`)
			goos = strings.TrimSuffix(goos, `":`)