Re: "pg_ctl: the PID file ... is empty" at end of make check

Thomas Munro <thomas(dot)munro(at)gmail(dot)com> writes:
> On Tue, Oct 15, 2019 at 1:55 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> and now prairiedog has shown it too:
>> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=prairiedog&dt=2019-10-14%2021%3A45%3A47
>> which is positively fascinating, because prairiedog is running a
>> bronze-age version of macOS that surely never heard of APFS.
>> So this makes it look like this is a basic macOS bug that's not
>> as filesystem-dependent as one might think.

> Does https://github.com/macdice/unlinktest show the problem on that system?

It does, though with a very low frequency:

$ ./unlinktest
$ ./unlinktest 10000
read 0 bytes, unexpected
$ ./unlinktest 10000
read 0 bytes, unexpected
read 0 bytes, unexpected
$ ./unlinktest 10000
$

The failure rate on my recent-vintage laptop is more like one
failure every five loops.

regards, tom lane