Try following your favourite distro's bug tracker during GCC upgrade. Practically every update breaks some packages, sometimes less, sometimes more (esp. when GCC changes their default flags).

Here's one example of workarounds in ~100 packages that broke when upgrading to GCC 10: https://github.com/search?q=repo%3ANixOS%2Fnixpkgs%20fcommon...

The Linux kernel was that way for a while, years ago.