no password

I can't seem to get this to work with anonymous as the username and an empty password.

if err = ftp.Login("anonymous", ""); err != nil {
panic(err)
}

it dies on ftp.Login

goroutine 1 [running]:
main.downloadDatabase()
ftp.go:30 +0x160
main.main()
init.go:7 +0x1b

goroutine 17 [syscall, locked to thread]:
runtime.goexit()
/usr/local/go/src/runtime/asm_amd64.s:2232 +0x1
exit status 2