Nginx - Nested locations and PHP-FPM

nested.conf

  # => YOURLS URL Shortener Configuration
  location /u/ {
    root /var/www/api/urls/;
    rewrite ^/(.*)/$ /$1/index.php last; # Enables index functionality (only really used for /u/admin/)
    rewrite ^/u/(.*)$ /$1 break; # Strips /u/ from the URI for static files
    try_files $uri /u/yourls-loader.php$is_args$args;

    # => API PHP-FPM
    location ~ \.php$ {
      fastcgi_split_path_info ^/u(.+?\.php)(.*)$;
      try_files $fastcgi_script_name =404;

      include /etc/nginx/fastcgi_params;
      fastcgi_index  index.php;
      fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
      #fastcgi_param  PATH_INFO        $fastcgi_path_info;
      #fastcgi_param  PATH_TRANSLATED  $document_root$fastcgi_path_info;
      fastcgi_pass   unix:/var/run/pipeline.sock;  # port where FastCGI processes were spawned
    }
  }

Oh boy, this saved my sanity after hours of pulling my hair off. What a clusterfuck nested locations are.