Today gcc-11.1.0 released upstream and was added to ::gentoo as: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=cc068d96fb49e308456cbe944fb29b1f78e6ad5c
User-visible changes are nicely described in upstream porting doc: https://gcc.gnu.org/gcc-11/porting_to.html A few highlights I personally encountered are: - use -std=gnu++17 instead of -std=gnu++14 - ordered pointer comparison with integer (like int *p; 'p > 0') - dynamic exception specifications - gcc now enforces that comparison objects be invocable as const - header dependency changes On top of that: - -fipa-modref (enabled by default) might expose latent bugs in existing programs. -fno-ipa-modref should be a quick hack to check the hypothesis. Failures don't look widespread, thus gcc-11 should be fine to use as a default compiler. Check out known bugs and workarounds on gcc-11 tracker: https://bugs.gentoo.org/show_bug.cgi?id=gcc-11 Gentoo Toolchain wiki page for common fixes (nothing there so far): https://wiki.gentoo.org/wiki/Project:Toolchain#gcc-11 As usual if you can't figure out what is wrong with your package pull in toolchain@ to the bug and we'll get to the bottom of it. Good luck! -- Sergei