Nginx + Passenger error_page setup

[ysorigin]

Im running a Merb project base on Nginx + Passenger, when the
application got error, it will raise 502 Bad Gateway page. so we want to
customize the error page. so we add these to the configuration file:

http{
    server{ 
      ....
      error_page 500 502 503 504 /500.html;
      location = /500.html {
        root /home/some_dir/;
      }
      ....
   }
]

but it couldn't work, I google a lot, but couldn't get correct solution,
am I miss sth?

thanks

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,213979,213979#msg-213979