GCC5 is the recently released new version of the Linux compiler. A vast number of packages need to be rebuilt to be compatible. This must be the biggest transition I have seen in my time of using Linux. Debian Sid and siduction users are having to hold off on upgrades presently, and probably for months.
How are other rolling-release distros handling this?
[ACHTUNG! URGENT!] GCC 5 TRANSITION, DO NOT DIST-UPGRADE or keep the pieces
https://release.debian.org/transitions/html/libstdc++6.html