x/crypto/ssh/test: TestAcceptCloseTCP failures

[gopherbot]

#!watchflakes
post <- pkg == "golang.org/x/crypto/ssh/test" && test == "TestAcceptCloseTCP" && `test timed out` && date <= "2023-06-15"

Issue created automatically to collect these failures.

Example (log):

panic: test timed out after 50m0s
running tests:
	TestAcceptCloseTCP (49m56s)

os/exec.(*Cmd).awaitGoroutines(0xc0000b6160, 0x0)
	/tmp/buildlet/go/src/os/exec/exec.go:941 +0x215
os/exec.(*Cmd).Wait(0xc0000b6160)
	/tmp/buildlet/go/src/os/exec/exec.go:908 +0x16d
golang.org/x/crypto/ssh/test.(*server).Shutdown(0xc0000f6090)
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/test_unix_test.go:249 +0x55
golang.org/x/crypto/ssh/test.testAcceptClose(0xc0002e9ba0, {0x1365751, 0x3}, {0x13674dd, 0xb})
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/forward_unix_test.go:150 +0x2b1
golang.org/x/crypto/ssh/test.TestAcceptCloseTCP(0x0?)
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/forward_unix_test.go:153 +0x2b
testing.tRunner(0xc0002e9ba0, 0x13968b0)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "golang.org/x/crypto/ssh/test" && test == "TestAcceptCloseTCP"

2023-05-08 17:07 darwin-amd64-longtest crypto@a4e98413 go@aa4d5e73 x/crypto/ssh/test.TestAcceptCloseTCP (log)

panic: test timed out after 50m0s
running tests:
	TestAcceptCloseTCP (49m56s)

os/exec.(*Cmd).awaitGoroutines(0xc0000b6160, 0x0)
	/tmp/buildlet/go/src/os/exec/exec.go:941 +0x215
os/exec.(*Cmd).Wait(0xc0000b6160)
	/tmp/buildlet/go/src/os/exec/exec.go:908 +0x16d
golang.org/x/crypto/ssh/test.(*server).Shutdown(0xc0000f6090)
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/test_unix_test.go:249 +0x55
golang.org/x/crypto/ssh/test.testAcceptClose(0xc0002e9ba0, {0x1365751, 0x3}, {0x13674dd, 0xb})
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/forward_unix_test.go:150 +0x2b1
golang.org/x/crypto/ssh/test.TestAcceptCloseTCP(0x0?)
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/forward_unix_test.go:153 +0x2b
testing.tRunner(0xc0002e9ba0, 0x13968b0)

— watchflakes

[bcmills]

This could plausibly be the same suspected kernel bug as #59892 and #54461.

[bcmills]

(attn @FiloSottile @rolandshoemaker @golang/security per https://dev.golang.org/owners)

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "golang.org/x/crypto/ssh/test" && test == "TestAcceptCloseTCP"

2023-05-08 17:07 darwin-amd64-longtest crypto@a4e98413 go@3afbca5c x/crypto/ssh/test.TestAcceptCloseTCP (log)

panic: test timed out after 50m0s
running tests:
	TestAcceptCloseTCP (49m57s)

os/exec.(*Cmd).awaitGoroutines(0xc0002b2160, 0x0)
	/tmp/buildlet/go/src/os/exec/exec.go:941 +0x215
os/exec.(*Cmd).Wait(0xc0002b2160)
	/tmp/buildlet/go/src/os/exec/exec.go:908 +0x16c
golang.org/x/crypto/ssh/test.(*server).Shutdown(0xc0002b0000)
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/test_unix_test.go:249 +0x55
golang.org/x/crypto/ssh/test.testAcceptClose(0xc0002b4d00, {0x136c121, 0x3}, {0x136dec3, 0xb})
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/forward_unix_test.go:150 +0x2b1
golang.org/x/crypto/ssh/test.TestAcceptCloseTCP(0xc0000722f0?)
	/tmp/buildlet/gopath/src/golang.org/x/crypto/ssh/test/forward_unix_test.go:153 +0x2b
testing.tRunner(0xc0002b4d00, 0x139d3e8)

— watchflakes

[gopherbot]

Change https://go.dev/cl/496935 mentions this issue: ssh/test: set a timeout and WaitDelay on sshd subcommands

[bcmills]

Should be worked around as of https://go.dev/cl/496935.

The broader macOS hang is still unaddressed, but not specific to this test.
(#54461 (comment))