Fedora glibc team, In the "Platform Interface" document [1] I talk about a distribution in which there is a distinction between what you run against and what you compile against. I had originally designed a new sysroot-glibc package which would be installed by default, and all applications would compile against that. However, in hindsight this is backwards to what users want. They key benefit I wanted was a bullet-proof way to avoid ABI breaks by using tooling. This would also help lower the bar for less senior developers contributing without the fear they would break the ABI. Consensus is that the normal day-to-day compilation against libraries like glibc should *not* change, and it should remain the normal process. Only users that want the newer glibc should have to add things to their build flags to link with a newer glibc. Likewise the newer glibc should be deployed as either a distinct package or in a distinct repository with the required packaging changes (provides all of it's interfaces in a sysroot, and a replacement runtime). If you are going to use the new glibc for compiling against then you must also install the new glibc for runtime. That is to say we support upgrading the development environment, but we do not support distinct cross-compilation (difficult to do without a lot of coordination on --prefix=/usr installed runtime data like locales, caches, etc). Therefore since I plan to retain a system glibc default installation that installation could benefit from more robust ABI checking, like we *would* have had if we compiled against a sysroot for the system glibc. The following two patches do just that. Patch 1/2 cleans up the glibc %install phase. Patch 2/2 introduces a process to record the ABI for all shared libraries, and then use that frozen ABI record to verify the ABI in great detail. This ABI checking is beyond what glibc does with *.abilist checking, and closer to what distributions are doing with their package release process (not yet standardized). Perhaps we will move this upstream one day when we've had more experience with it in Fedora. We currently rely on libabigail for ABI serialization. -- Cheers, Carlos. [1] https://fedoraproject.org/wiki/PlatformInterface