GCC is an important component in Linux distros and upgrading it is an important step. Any major changes to GCC (GNU Compiler Collection) can bring a host of problems, so any decision in this regard will care a lot of weight.

Ubuntu developers have decided to upgrade the GCC package for the upcoming Ubuntu 15.10 (Wily Werewolf), and they are asking everyone to start testing the new changes once they are implemented. It's important that they do this before the LTS version of Ubuntu that will arrive in 2016. If developers do encounter problems with it, they need to make sure that they don't have any major issues with an LTS version that is supported for five years.

For example, the Fedora project upgrades GNU Compiler Collection to a new version during their previous development cycle, and it turned out to be a problem. They had to recompile everything in the OS, and the launch was delayed by a couple of weeks. Given that Ubuntu is the most used Linux operating system around and that a lot of distros are using it as a base, any issue with GCC would bleed out in a very short time.

GCC 5 is coming by default in Ubuntu 15.10

It will take a while to make the transition, but Ubuntu 15.10 is not a major release in the grand scheme of things, and there is plenty to make sure that everything is going according to plan. In any case, regular users won't be able to tell the difference, and nothing significantly will change, at least from their perspective.

"GCC 5 will be the default compiler for the wily release, and it's time to prepare the change of the default in wily, so that we don't have to do it during the next release cycle before the next LTS release. This time things are a bit more complicated, we basically need to rebuild all C++ packages using g++ 5, and we are not able to fall back to a newer compiler," wrote Matthias Klose.

He's also working for the same transition in Debian, and it looks like both projects will be in sync, at least for this package.