Someone else had the same problem...
https://lists.amavis.org/pipermail
/amavis-users/2015-April/003549.html
On Do, 2016-09-01 at 18:52 -0400, Bugs in Net-Server via RT wrote:
Show quoted text> Greetings,
>
> This message has been automatically generated in response to the
> creation of a trouble ticket regarding:
> "NS_port is empty when using UNIX sockets",
> a summary of which appears below.
>
> There is no need to reply to this message right now. Your ticket has
> been
> assigned an ID of [rt.cpan.org #117422]. Your ticket is accessible
> on the web at:
>
>
https://rt.cpan.org/Ticket/Display.html?id=117422
>
> Please include the string:
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> [rt.cpan.org #117422]
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> bug-Net-Server@rt.cpan.org
>
> -------------------------------------------------------------------
> ------
> I'm using amavisd-new 2.11.0 and I get this error when postfix tries
> to
> connect to the unix socket:
>
> Net::Server: 2016/09/01-18:05:16 CONNECT UNIX Socket: ""
>
> When installing Net::Server 0.97 or 0.99 everything is fine.
> Git bisect gave me two commits (
https://github.com/rhandom/perl-net-s
> er
> ver) where the bug maybe came in:
> 58b71ff6a83f0bd6153ebdbe193dfe22b792ca87
> 97bccf2a8f9f5a599eaf516ee2167a1cf16fda84
>