nginx fastcgi "Primary script unknown" when configuring userdir

I hate configuring nginx. It's so complicated. How do I get PHP to work in my user dirs? Here's the relevant part of my nginx.conf:

    location ~ ^/~(.+?)(/.*)?$ {
        autoindex on;
        autoindex_exact_size off;
        alias /home/$1/public_html$2;

        location ~ \.php {
            include /etc/nginx/fastcgi.conf;
            fastcgi_intercept_errors on;
            fastcgi_pass  127.0.0.1:9000;
            fastcgi_index index.php;
        }
    }

This gives me the error: FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream in the nginx error log.

Here's my /etc/nginx/fastcgi.conf:

fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;
fastcgi_param  QUERY_STRING       $query_string;
fastcgi_param  REQUEST_METHOD     $request_method;
fastcgi_param  CONTENT_TYPE       $content_type;
fastcgi_param  CONTENT_LENGTH     $content_length;

fastcgi_param  SCRIPT_NAME        $fastcgi_script_name;
fastcgi_param  REQUEST_URI        $request_uri;
fastcgi_param  DOCUMENT_URI       $document_uri;
fastcgi_param  DOCUMENT_ROOT      $document_root;
fastcgi_param  SERVER_PROTOCOL    $server_protocol;
fastcgi_param  HTTPS              $https if_not_empty;

fastcgi_param  GATEWAY_INTERFACE  CGI/1.1;
fastcgi_param  SERVER_SOFTWARE    nginx/$nginx_version;

fastcgi_param  REMOTE_ADDR        $remote_addr;
fastcgi_param  REMOTE_PORT        $remote_port;
fastcgi_param  SERVER_ADDR        $server_addr;
fastcgi_param  SERVER_PORT        $server_port;
fastcgi_param  SERVER_NAME        $server_name;

# PHP only, required if PHP was built with --enable-force-cgi-redirect
fastcgi_param  REDIRECT_STATUS    200;

I'm assuming nginx isn't resolving the script name correctly. I hate having to tell nginx where to look in my filesystem, writing custom regexes for what should be built-in (or at least standardized and documented) functionality.

Problem is that in your fastcgi.conf you define SCRIPT_FILENAME as $document_root$fastcgi_script_name; but you then use the alias direcive to set the path.

You should update your SCRIPT_FILENAME to use $request_filename

You can also go back to nested location if you prefer. If you still get this error afterwards then I have documented all the possibilities here: http://blog.martinfjordvald.com/2011/01/no-input-file-specified-with-php-and-nginx/

Please check that as there can be multiple other causes.

When You define redirects, aliases and You do use fastcgi in the conf of your site in nginx You can try this to let them work:

Change:

location ~ \.php$ {
...
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
...
}

Into:

location ~ \.php$ {
...
fastcgi_param SCRIPT_FILENAME $request_filename;
fastcgi_param REQUEST_URI $uri?$args;
...
}

If this does not work try to use as said above without the REQUEST_URI, so it will be:

location ~ \.php$ {
...
fastcgi_param SCRIPT_FILENAME $request_filename;
...
}

Try using a separate location block for PHP scripts in the userdirs. This does not need to be nested.

location ~ ^/~([^/]+)/(.+\.php)$ {
    alias /home/$1/public_html/$2;
    include /etc/nginx/fastcgi.conf;
    fastcgi_intercept_errors on;
    fastcgi_pass  127.0.0.1:9000;
    fastcgi_index index.php;
}