From a performance and enthusiast perspective, what I personally find most disappointing and puzzling with the imminent release of Ubuntu 26.10 comes down to its default compiler version.

Typically with every Ubuntu xx.10 October release is when they pull in the latest major version of the GNU Compiler Collection (GCC) of that year. GCC 15 in Ubuntu 25.10, GCC 14 in Ubuntu 24.10, etc. That's worked out well for them with the annual GCC feature release coming in March~April each year and too close for the Ubuntu xx.04 release.

For as far as my memory serves me, it's always been that way of the Ubuntu xx.10 release seeing the new GCC compiler as the default for what's provided by build-essential and friends. GCC 16 released on schedule earlier this year and surprisingly, Ubuntu 26.10 is still defaulting to GCC 15 rather than this year's GCC 16 release.

There is a gcc-16 package in Ubuntu 26.10, but it's not the default compiler. That's disappointing for those accustomed to just using build-essential or other default provides. GCC 16 brings many improvements from better error messages to Arm AGI CPU support and initial AMD Zen 6 "znver6" support. Thus unfortunate and surprising to see GCC 15 used by default rather than GCC 16.

I haven't found any public explanation for this change or there the lack of in keeping the default at GCC 15 for Ubuntu 26.10. Namely publishing this post for raising awareness for those also accustomed to finding the newest GCC version as the default in Ubuntu xx.10.