running phpmyadmin on non-standard dir

[maxxer]

hi. I'm new to Nginx.
I'd like to make serve phpmyadmin on a non-standard url.
I'm on debian, and following this howto works great:
http://rubyist-journal.com/2010/02/28/howto-nginx-php5-mysql-phpmyadmin-ubuntu-shortest-setup/

but if I change it this way:

    location /pma {
           root /usr/share/phpmyadmin/;
           index index.php index.html index.htm;
           location ~ ^/(.+\.php)$ {
                   try_files $uri =404;
                   root /usr/share/phpmyadmin/;
                   fastcgi_pass   backend;
                   fastcgi_param HTTPS $fastcgi_https;
                   fastcgi_index index.php;
                   fastcgi_param SCRIPT_FILENAME
$document_root$request_filename;
                   include /etc/nginx/fastcgi_params;
           }   
    }   

I just get 404.
2 questions:
* how to make it properly work?
* how to debug these config errors?

thanks a lot!
maxxer

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,221927,221927#msg-221927