当我使用标志包时

// main.go

import (
  ...
  "flag"  
)

func main() {
  ...
  flag.Parse()

  switch flag.Arg(0) {
  case "doSomething1":
    ...
  case "doSomething2":
    ...
  }

}

如果doSomething1参数为我打印了一些错误消息，无论我如何修复源代码，它都无法删除旧的错误代码并重新编译。

// 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