net: TestCloseWrite for SOCK_SEQPACKET failing on SmartOS

[bcmills]

Looking at the recent test flakes on solaris-amd64-smartosbuildlet, the vast majority of them are failures in TestCloseWrite.

For an example, see https://build.golang.org/log/f41d2e44b0629db5f3b5e32eec5751b465f4717f:

--- FAIL: TestCloseWrite (0.00s)
    net_test.go:153: got (0, read unixpacket ->/tmp/workdir/tmp/go-nettest264897916: not pollable); want (0, io.EOF)
FAIL
FAIL	net	9.459s

CC @mikioh @bradfitz @ianlancetaylor

[ianlancetaylor]

Most likely due to https://golang.org/cl/166497 "runtime, internal/poll, net: report event scanning error on read event". I suspect that Solaris poll is reporting POLLERR if the other side of a Unix socket is closed, although the man page is uninformative on the point. It would be interesting to know whether POLLHUP was also set.

[mikioh]

Sure, I think the fix for #30817 also cures this issue.

[gopherbot]

Change https://golang.org/cl/167777 mentions this issue: runtime, internal/poll: report only critical event scanning error

[mikioh]

Reopen: it seems like there's something-something between Oracle Solaris and SmartOS.

[gopherbot]

Change https://golang.org/cl/167782 mentions this issue: runtime: disable event scanning error reporting on solaris