當我使用標志包時// main.goimport (  ...  "flag"  )func main() {  ...  flag.Parse()  switch flag.Arg(0) {  case "doSomething1":    ...  case "doSomething2":    ...  }}如果 doSomething1 參數為我打印一些錯誤消息，無論我修復源代碼，它都無法刪除舊的錯誤代碼并再次編譯。// command-line# go build ./main.go# ./main doSomething1# error doSomething1 can not work-- I fix my code# ./main doSomething1# error doSomething1 can not work-- the error message also show me again-- I have to delete main and build again# rm ./main# go build ./main.go# ./main.go doSomething1# doSomething1 now can work