A new c compiler will be introduced in 15.10. This is going to require a major rebuild of the core packages for both desktop and phone. We need to keep our eyes on this when testing starts. http://linux.softpedia.com/blog/Ubuntu-15-10-Wily-Werewolf-to-Come-with-GCC-5-Ubuntu-16-04-LTS-with-Python-3-480719.shtml