Merge "Improve error handling around username/hostname"

	envFunc(cmd.Environment)

	if _, ok := cmd.Environment.Get("BUILD_USERNAME"); !ok {

		u, err := user.Current()

		if err != nil {

			ctx.Println("Failed to get current user")

		username := "unknown"

		if u, err := user.Current(); err == nil {

			username = u.Username

		} else {

			ctx.Println("Failed to get current user:", err)

		}

		cmd.Environment.Set("BUILD_USERNAME", u.Username)

		cmd.Environment.Set("BUILD_USERNAME", username)

	}

	if _, ok := cmd.Environment.Get("BUILD_HOSTNAME"); !ok {

		hostname, err := os.Hostname()

		if err != nil {

			ctx.Println("Failed to read hostname")

			ctx.Println("Failed to read hostname:", err)

			hostname = "unknown"

		}

		cmd.Environment.Set("BUILD_HOSTNAME", hostname)

	}