startup error -> "[emerg] duplicate listen options" if 2nd IPv6 listener is enabled

[pgn]

Sorry, I don't understand your point.

Why is this ok, and fully functional? 
---------------------------------
server { server_name test1.loc;
listen 10.0.0.1:443;
...
server {server_name test2.loc;
listen 10.0.0.1:443;
...
---------------------------------

but this is not?
---------------------------------
server { server_name test1.loc;
listen [2001:xxx:xxxx:xxx::1]:443 ipv6only=on;
...
server {server_name test2.loc;
listen [2001:xxx:xxxx:xxx::1]:443 ipv6only=on;
...
---------------------------------


In BOTH cases, BOTH server{} are listening on the same address:port,
differentiated by server_name for vhost redirection.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,228250,228253#msg-228253