Re: postmaster became multithreaded

On Tue, Apr 11, 2017 at 10:56:00PM -0400, Noah Misch wrote:
> On Tue, Mar 28, 2017 at 04:32:44PM -0400, Tom Lane wrote:
> > Wayne Pichotta <wpichotta(at)truecar(dot)com> writes:
> > > I just saw this in my logs:
> > > LOG: postmaster became multithreaded
> > > DETAIL: Please report this to <pgsql-bugs(at)postgresql(dot)org>.

Reporter sent additional facts offline. Root cause was interference from
antivirus software.

> /*
> * On macOS, libintl replaces setlocale() with a version that calls
> * CFLocaleCopyCurrent() when its second argument is "" and every relevant
> * environment variable is unset or empty. CFLocaleCopyCurrent() makes
> * the process multithreaded.
>
> The reported message might be explained by starting the server with
> lc_messages='something' in postgresql.conf, then deleting that line from
> postgresql.conf and reloading the configuration.

On further reflection, that sequence of actions would not elicit the reported
message. Startup would fail with "postmaster became multithreaded during
startup" before you could complete the rest of that sequence.