os/exec: TestIgnorePipeErrorOnSuccess/10MB often hangs on netbsd-amd64-71 #20835
Description
As of e1ced32 (just past Go1.9beta2), I see occasional hangs during os/exec's TestIgnorePipeErrorOnSuccess/10MB on netbsd-amd64-71 (NetBSD 7.1).
With gomote, it sometimes hangs in:
$ gomote run $MOTE go/bin/go test -short -v os/exec
=== RUN TestDedupEnv
--- PASS: TestDedupEnv (0.00s)
=== RUN TestPrefixSuffixSaver
--- PASS: TestPrefixSuffixSaver (0.00s)
=== RUN TestLookPathNotFound
--- PASS: TestLookPathNotFound (0.00s)
=== RUN TestLookPathUnixEmptyPath
--- PASS: TestLookPathUnixEmptyPath (0.00s)
=== RUN TestCredentialNoSetGroups
--- PASS: TestCredentialNoSetGroups (0.00s)
=== RUN TestWaitid
=== RUN TestEcho
--- PASS: TestEcho (0.00s)
=== RUN TestCommandRelativeName
--- PASS: TestCommandRelativeName (0.00s)
=== RUN TestCatStdin
--- PASS: TestCatStdin (0.00s)
=== RUN TestEchoFileRace
--- PASS: TestEchoFileRace (0.00s)
=== RUN TestCatGoodAndBadFile
--- PASS: TestCatGoodAndBadFile (0.03s)
=== RUN TestNoExistBinary
--- PASS: TestNoExistBinary (0.00s)
=== RUN TestExitStatus
--- PASS: TestExitStatus (0.00s)
=== RUN TestPipes
--- PASS: TestPipes (0.01s)
=== RUN TestStdinClose
--- PASS: TestStdinClose (0.02s)
=== RUN TestStdinCloseRace
--- PASS: TestStdinCloseRace (0.02s)
=== RUN TestPipeLookPathLeak
--- PASS: TestPipeLookPathLeak (0.00s)
=== RUN TestExtraFilesFDShuffle
--- SKIP: TestExtraFilesFDShuffle (0.00s)
exec_test.go:422: flaky test; see https://golang.org/issue/5780
=== RUN TestExtraFiles
--- PASS: TestExtraFiles (0.06s)
exec_test.go:416: TestExtraFiles: Something already leaked - closed fd 7
exec_test.go:416: TestExtraFiles: Something already leaked - closed fd 8
exec_test.go:416: TestExtraFiles: Something already leaked - closed fd 9
=== RUN TestExtraFilesRace
--- PASS: TestExtraFilesRace (0.07s)
=== RUN TestHelperProcess
--- PASS: TestHelperProcess (0.00s)
=== RUN TestIgnorePipeErrorOnSuccess
=== RUN TestIgnorePipeErrorOnSuccess/10MB
^C