Misconfigured nginx + HHVM? Some PHP globals (WordPress) are empty

I just played around with nginx + HHVM + WordPress, but can’t get it to work correctly. Apache + HHVM and nginx + PHP-FPM works, but when using nginx and HHVM together, some global PHP variables are empty.

For example, there is a global called nice_options in my theme.

When trying this:

global $nice_options;   

echo '###';
print_r($nice_options);
print_r($_GLOBALS['nice_options']);
echo '###'; 

I get this: ######.

I even tried to print_r($GLOBALS)and noticed, that [nice_options] is empty, but fully available in wp_object_cache.

I’m using Ubuntu 14.04, nginx 1.6.0 and HHVM 3.

My nginx configuration files:

/etc/nginx/nginx.conf

user www-data;
worker_processes 4;
pid /run/nginx.pid;

events {
    worker_connections 768;
    # multi_accept on;
}

http {

    ##
    # Basic Settings
    ##

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    # server_tokens off;

    # server_names_hash_bucket_size 64;
    # server_name_in_redirect off;

    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    ##
    # Logging Settings
    ##

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;

    ##
    # Gzip Settings
    ##

    gzip on;
    gzip_disable "msie6";

    # gzip_vary on;
    # gzip_proxied any;
    # gzip_comp_level 6;
    # gzip_buffers 16 8k;
    # gzip_http_version 1.1;
    # gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;

    ##
    # nginx-naxsi config
    ##
    # Uncomment it if you installed nginx-naxsi
    ##

    #include /etc/nginx/naxsi_core.rules;

    ##
    # nginx-passenger config
    ##
    # Uncomment it if you installed nginx-passenger
    ##
    
    #passenger_root /usr;
    #passenger_ruby /usr/bin/ruby;

    ##
    # Virtual Host Configs
    ##

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
}

/etc/nginx/sites-available/chefgrill (name of my domain)

server {
  listen 80 default_server;  
  
  root /var/www/chefgrill.de/public_html;
  access_log /var/www/chefgrill.de/logs/access.log;
  error_log /var/www/chefgrill.de/logs/error.log;
  index index.php;

  server_name dev.chefgrill.de;

  location / {
    try_files $uri $uri/ /index.php?q=$uri&$args;
  }

  location ~* .(jpg|jpeg|gif|css|png|js|ico|html)$ {
    access_log off;
    expires max;
  }

  location ~ /.ht {
    deny  all;
  }

  include hhvm.conf;

}

/etc/nginx/hhvm.conf

location ~ .(hh|php)$ {
    fastcgi_keep_conn on;
    fastcgi_pass   127.0.0.1:9000;
    fastcgi_index  index.php;
    fastcgi_param  SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_read_timeout 1000; 
    include        fastcgi_params;
}