Just try to setup limesurvey 2.5RC2 on my CentOS6.6 64bit on my VirtualBox VM, using Nginx, not Apache.
but always got below message when I tried to visit http://192.168.7.104:8095/index.php, I have tried chmod 766 or 776 or 777 for the dir of /usr/local/limesurvey and all dirs and files under it, but useless.

/usr/local/limesurvey/tmp/runtime should be writable by the webserver (766 or 776).

I am wandering if my nginx.conf is not good, do you have any suggestion about this. Thanks in advance.
And also would like to know if there is a schedule for the stable version of 2.5.

limesurvey250RC2-build151008.tar.gz
PHP5.5.29 With php5-fpm
Nginx 1.9.5

here is my nginx.conf:
server {
listen 8095;
server_name 192.168.7.104;
root /usr/local/limesurvey;
index index.php index.html index.htm;
access_log logs/survey.access.log main;
error_log logs/survey.error.log error;

location / {
#try_files $uri = 404;
try_files $uri $uri/ /index.php;
}

location ~ (^\.|/\.) {
return 403;
}

location ~ \.php$ {
fastcgi_split_path_info ^(.+\.php)(/.+)$;
# NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini

# With php5-cgi alone:
#fastcgi_pass 127.0.0.1:9000;
# With php5-fpm:
fastcgi_pass unix:/var/run/php5-fpm.sock;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME /usr/local/limesurvey$fastcgi_script_name;
include fastcgi_params;
}
}

I also have this problem. Could you please share what you did to resolve this?

UPDATE: Solved!
In my case, selinux was preventing php-fpm from writing to some folders. This is how I fixed it:

Why would you install 2.5 RC2 if there are much newer versions out there?