Does setting a variable only work once?

[Michael Shadle]

neither of these work. it only takes the first $port, the second one is ignored

                set $port 11019;
                root /home/foo/web/bar.com;
                include /etc/nginx/expires.conf;
                include /etc/nginx/confs/phpmyadmin.conf;
                location /sites {
                        set $port 11003;
                        include /etc/nginx/confs/sites.conf;
                }
or
                set $port 11019;
                root /home/foo/web/bar.com;
                include /etc/nginx/expires.conf;
                include /etc/nginx/confs/phpmyadmin.conf;
                set $port 11003;
                include /etc/nginx/confs/sites.conf;