x/playground: exec.Cmd.StdoutPipe() example: all goroutines are asleep

[bfallik]

Go version

unknown

Output of go env in your module/workspace:

unknown

What did you do?

Ran the example code here: https://pkg.go.dev/os/exec#example-Cmd.StdoutPipe

What did you see happen?

Output:

fatal error: all goroutines are asleep - deadlock!

goroutine 1 [IO wait]:
internal/poll.runtime_pollWait(0x7ee60f415680, 0x72)
	/usr/local/go-faketime/src/runtime/netpoll.go:351 +0x85
internal/poll.(*pollDesc).wait(0xc000078240?, 0xc00010e000?, 0x1)
	/usr/local/go-faketime/src/internal/poll/fd_poll_runtime.go:84 +0x27
internal/poll.(*pollDesc).waitRead(...)
	/usr/local/go-faketime/src/internal/poll/fd_poll_runtime.go:89
internal/poll.(*FD).Read(0xc000078240, {0xc00010e000, 0x200, 0x200})
	/usr/local/go-faketime/src/internal/poll/fd_unix.go:165 +0x27a
os.(*File).read(...)
	/usr/local/go-faketime/src/os/file_posix.go:29
os.(*File).Read(0xc00004c048, {0xc00010e000?, 0x28?, 0x512380?})
	/usr/local/go-faketime/src/os/file.go:124 +0x52
encoding/json.(*Decoder).refill(0xc00010c000)
	/usr/local/go-faketime/src/encoding/json/stream.go:165 +0x188
encoding/json.(*Decoder).readValue(0xc00010c000)
	/usr/local/go-faketime/src/encoding/json/stream.go:140 +0x85
encoding/json.(*Decoder).Decode(0xc00010c000, {0x4efe60, 0xc000010030})
	/usr/local/go-faketime/src/encoding/json/stream.go:63 +0x75
main.main()
	/tmp/sandbox2132264063/prog.go:23 +0x193

What did you expect to see?

Program output instead of the fatal error.

[gabyhelp]

Related Issues

• x/playground: falsely detects a deadlock when running Cmd.StderrPipe example code #41202
• Deadlock error in documentation example code #41609 (closed)
• os/exec: incorrect "fatal error: all goroutines are asleep - deadlock!" #41271 (closed)
• runtime: os/exec fatal error: all goroutines are asleep - deadlock! on mips64 #42825
• x/website: Inside the Go Playground - Faking the network example error #53731 (closed)
• affected/package: os/exec, context not work. #53700 (closed)
• os/exec: cmd.Start got a deadlock when set cmd.Stdin #47061 (closed)
• cmd/go: tests timing out on linux-amd64 #21850 (closed)
• os/exec: CombinedOutput hangs when exec'd task forks a "daemon" #13155 (closed)
• os/exec: possible race handling stdout&stderr pipes #69060

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[seankhliao]

Duplicate of #41202