cmd.StdoutPipego 文檔中的示例：https ://pkg.go.dev/os/exec#example-Cmd.StdoutPipe不在操場上運行。https://play.golang.org/p/ek7-_Xa_bN3錯誤：fatal error: all goroutines are asleep - deadlock!goroutine 1 [IO wait]:internal/poll.runtime_pollWait(0x7faec2ac4e88, 0x72)    /usr/local/go-faketime/src/runtime/netpoll.go:234 +0x89internal/poll.(*pollDesc).wait(0xc000074180, 0xc000100000, 0x1)    /usr/local/go-faketime/src/internal/poll/fd_poll_runtime.go:84 +0x32internal/poll.(*pollDesc).waitRead(...)    /usr/local/go-faketime/src/internal/poll/fd_poll_runtime.go:89internal/poll.(*FD).Read(0xc000074180, {0xc000100000, 0x200, 0x200})    /usr/local/go-faketime/src/internal/poll/fd_unix.go:167 +0x25aos.(*File).read(...)    /usr/local/go-faketime/src/os/file_posix.go:32os.(*File).Read(0xc00000e028, {0xc000100000, 0x28, 0xc000060e80})    /usr/local/go-faketime/src/os/file.go:119 +0x5eencoding/json.(*Decoder).refill(0xc00007e000)    /usr/local/go-faketime/src/encoding/json/stream.go:165 +0x17fencoding/json.(*Decoder).readValue(0xc00007e000)    /usr/local/go-faketime/src/encoding/json/stream.go:140 +0xbbencoding/json.(*Decoder).Decode(0xc00007e000, {0x4cf580, 0xc00000c048})    /usr/local/go-faketime/src/encoding/json/stream.go:63 +0x78main.main()    /tmp/sandbox2294589397/prog.go:24 +0x185Program exited.在本地它運行正常，沒有死鎖。我無法理解為什么在 go playground 中會發生死鎖。