Runtime Error: Index out of range when attempting to os.StartProcess

I can't seem to figure out why it's doing this:

I have a function setup like this:

func (srv *Server) StartServer() {
  // Some stuff to make sure paths are correct

  path := srv.Path + "server.exe"
  var args = []string{
    "ip=" + srv.IP,
    "un=" + srv.Username,
    "pw=" + srv.Password
  }
  proc, err := os.StartProcess(path, args, new(os.ProcAttr))
  if err != nil {
    panic(err)
  }
}

The StartProcess method throws an index out of range.

I'm probably just missing something, but I just can't see it.

Exact error as requested:

panic: runtime error: index out of range

goroutine 1 [running]:
syscall.StartProcess(0xc082052b70, 0x21, 0xc08200a6e0, 0x5, 0x5, 0xc08201dd60, 0x0, 0x0, 0x0, 0x0)
        c:/go/src/syscall/exec_windows.go:322 +0x94c
os.startProcess(0xc082052b70, 0x21, 0xc08200a6e0, 0x5, 0x5, 0xc08200a730, 0x5217e0, 0x0, 0x0)
        c:/go/src/os/exec_posix.go:45 +0x482
os.StartProcess(0xc082052b70, 0x21, 0xc08200a6e0, 0x5, 0x5, 0xc08200a730, 0x0, 0x0, 0x0)
        c:/go/src/os/doc.go:24 +0x79
main.(*Server).StartServer(0x5efae0)
        E:/build_test/SrvMgr.go:85 +0x4e6
main.main()
        E:/build_test/SrvMgr.go:54 +0x141

goroutine 2 [runnable]:
runtime.forcegchelper()
        c:/go/src/runtime/proc.go:90
runtime.goexit()
        c:/go/src/runtime/asm_amd64.s:2232 +0x1

goroutine 3 [runnable]:
runtime.bgsweep()
        c:/go/src/runtime/mgc0.go:82
runtime.goexit()
        c:/go/src/runtime/asm_amd64.s:2232 +0x1

goroutine 4 [runnable]:
runtime.runfinq()
        c:/go/src/runtime/malloc.go:712
runtime.goexit()
        c:/go/src/runtime/asm_amd64.s:2232 +0x1
exit status 2

Edit: Link to a simplified play.golang post reproducing it. I'm running go version 1.4.2 win/amd64

http://play.golang.org/p/S6kRLMyd2I

You are getting the error because you do not set the file descriptors for Stderr and Stdout on your os.ProcAttr. It seems those get set automatically on linux, but you need to set them on windows.

This is a working example:

func (srv *Server) StartServer() {
  // Some stuff to make sure paths are correct

  path := srv.Path + "server.exe"
  var args = []string{
    "ip=" + srv.IP,
    "un=" + srv.Username,
    "pw=" + srv.Password
  }
  var attr os.ProcAttr
  attr.Files = []*os.File{nil, os.Stdout, os.Stderr}
  proc, err := os.StartProcess(path, args, &attr)
  if err != nil {
    panic(err)
  }
}