Re: [GENERAL] pg_upgrade from 9.5 to 9.6 fails with "invalid argument"

Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Tom Lane wrote:
>> I wouldn't even put a lot of faith in the errno being meaningful,
>> considering that it does close() calls before capturing the errno.

> So we do close() in a bunch of places while closing shop, which calls
> _close() on Windows; this function sets errno.

But only on failure, no?  The close()s usually shouldn't fail, and
therefore shouldn't change errno, it's just that you can't trust that
100%.

I think likely what's happening is that we're seeing a leftover value from
some previous syscall that set GetLastError's result (and, presumably,
wasn't fatal so far as pg_upgrade was concerned).
        regards, tom lane