So, what do you do when you have to install a new patch level release of said glibc? Rebuild every single component on the system? I take it configuration of t

So, what do you do when you have to install a new patch level release of said glibc? Rebuild every single component on the system? I take it configuration of the packages needs to go in nix as well? So what do you do when there is, for example, a change of upstream smtp?