os: TestGetwdDeepWithPWDSet failures

[gopherbot]

#!watchflakes
default <- pkg == "os" && test == "TestGetwdDeepWithPWDSet"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestGetwdDeepWithPWDSet
    getwd_unix_test.go:57:  $PWD len: 253
    getwd_unix_test.go:61: Getwd len: 253
    getwd_unix_test.go:57:  $PWD len: 454
    getwd_unix_test.go:61: Getwd len: 454
    getwd_unix_test.go:57:  $PWD len: 655
    getwd_unix_test.go:61: Getwd len: 655
    getwd_unix_test.go:57:  $PWD len: 856
    getwd_unix_test.go:61: Getwd len: 856
    getwd_unix_test.go:57:  $PWD len: 1057
    getwd_unix_test.go:61: Getwd len: 0
    getwd_unix_test.go:69: getwd: file name too long
--- FAIL: TestGetwdDeepWithPWDSet (0.00s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "os" && test == "TestGetwdDeepWithPWDSet"

2024-11-06 00:40 gotip-darwin-amd64_11 go@d98c5180 os.TestGetwdDeepWithPWDSet (log)

=== RUN   TestGetwdDeepWithPWDSet
    getwd_unix_test.go:57:  $PWD len: 253
    getwd_unix_test.go:61: Getwd len: 253
    getwd_unix_test.go:57:  $PWD len: 454
    getwd_unix_test.go:61: Getwd len: 454
    getwd_unix_test.go:57:  $PWD len: 655
    getwd_unix_test.go:61: Getwd len: 655
    getwd_unix_test.go:57:  $PWD len: 856
    getwd_unix_test.go:61: Getwd len: 856
    getwd_unix_test.go:57:  $PWD len: 1057
    getwd_unix_test.go:61: Getwd len: 0
    getwd_unix_test.go:69: getwd: file name too long
--- FAIL: TestGetwdDeepWithPWDSet (0.00s)

2024-11-18 02:09 gotip-darwin-amd64_11 go@90b1dc01 os.TestGetwdDeepWithPWDSet (log)

=== RUN   TestGetwdDeepWithPWDSet
    getwd_unix_test.go:57:  $PWD len: 272
    getwd_unix_test.go:61: Getwd len: 272
    getwd_unix_test.go:57:  $PWD len: 473
    getwd_unix_test.go:61: Getwd len: 473
    getwd_unix_test.go:57:  $PWD len: 674
    getwd_unix_test.go:61: Getwd len: 674
    getwd_unix_test.go:57:  $PWD len: 875
    getwd_unix_test.go:61: Getwd len: 875
    getwd_unix_test.go:57:  $PWD len: 1076
    getwd_unix_test.go:61: Getwd len: 0
    getwd_unix_test.go:69: getwd: file name too long
--- FAIL: TestGetwdDeepWithPWDSet (0.00s)

2024-11-20 18:45 gotip-darwin-amd64_11 go@e1dc707f os.TestGetwdDeepWithPWDSet (log)

=== RUN   TestGetwdDeepWithPWDSet
    getwd_unix_test.go:57:  $PWD len: 254
    getwd_unix_test.go:61: Getwd len: 254
    getwd_unix_test.go:57:  $PWD len: 455
    getwd_unix_test.go:61: Getwd len: 455
    getwd_unix_test.go:57:  $PWD len: 656
    getwd_unix_test.go:61: Getwd len: 656
    getwd_unix_test.go:57:  $PWD len: 857
    getwd_unix_test.go:61: Getwd len: 857
    getwd_unix_test.go:57:  $PWD len: 1058
    getwd_unix_test.go:61: Getwd len: 0
    getwd_unix_test.go:69: getwd: file name too long
--- FAIL: TestGetwdDeepWithPWDSet (0.01s)

2024-11-22 03:48 gotip-darwin-amd64_11 go@dbfd0036 os.TestGetwdDeepWithPWDSet (log)

=== RUN   TestGetwdDeepWithPWDSet
    getwd_unix_test.go:57:  $PWD len: 273
    getwd_unix_test.go:61: Getwd len: 273
    getwd_unix_test.go:57:  $PWD len: 474
    getwd_unix_test.go:61: Getwd len: 474
    getwd_unix_test.go:57:  $PWD len: 675
    getwd_unix_test.go:61: Getwd len: 675
    getwd_unix_test.go:57:  $PWD len: 876
    getwd_unix_test.go:61: Getwd len: 876
    getwd_unix_test.go:57:  $PWD len: 1077
    getwd_unix_test.go:61: Getwd len: 0
    getwd_unix_test.go:69: getwd: file name too long
--- FAIL: TestGetwdDeepWithPWDSet (0.00s)

— watchflakes

[dmitshur]

This is a continuation of #69234 (comment). So far, these particular failures seem to only happen on the darwin/amd64 builders with macOS 11.

[ianlancetaylor]

CC @kolyshkin

[ianlancetaylor]

This passes on the gotip-darwin-amd64_11 gomote.

% go test -test.v -test.run=TestGetwdDeepWithPWD os
=== RUN   TestGetwdDeepWithPWDSet
    getwd_unix_test.go:57:  $PWD len: 272
    getwd_unix_test.go:61: Getwd len: 272
    getwd_unix_test.go:57:  $PWD len: 473
    getwd_unix_test.go:61: Getwd len: 473
    getwd_unix_test.go:57:  $PWD len: 674
    getwd_unix_test.go:61: Getwd len: 674
    getwd_unix_test.go:57:  $PWD len: 875
    getwd_unix_test.go:61: Getwd len: 875
    getwd_unix_test.go:57:  $PWD len: 1076
    getwd_unix_test.go:61: Getwd len: 1076
    getwd_unix_test.go:100: Done; len(wd)=1076
--- PASS: TestGetwdDeepWithPWDSet (0.00s)
PASS
ok  	os	0.009s

Even if I get the lengths to match the error message exactly, it passes. Not sure what is going on here.

[linsite]

hi @ianlancetaylor, 1076 does exceeds the Drawin MAXPATH=1024. To me, it most likely failed at the 'general algorithm' branch as below.

go/src/os/getwd.go

Lines 108 to 120 in 6405e60

	for {
	names, err := fd.Readdirnames(100)
	if err != nil {
	fd.Close()
	// Readdirnames can return io.EOF or other error.
	// In any case, we're here because syscall.Getwd
	// is not implemented or failed with ENAMETOOLONG,
	// so return the most sensible error.
	if syscall.ImplementsGetwd {
	return "", NewSyscallError("getwd", syscall.ENAMETOOLONG)
	}
	return "", NewSyscallError("getwd", errENOSYS)
	}

I guess it there any way to reveal the err in line 110 in tests, then there will be more details.