This should be fairly straightforward with overlays (https://nixos.wiki/wiki/Overlays https://nixos.wiki/wiki/Overlays) right? Just overlay libc package with th

This should be fairly straightforward with overlays (https://nixos.wiki/wiki/Overlays https://nixos.wiki/wiki/Overlays) right? Just overlay libc package with the version you want to use. The main disadvantage of doing this is that you lose the binary cache and will need to rebuild your system from scratch. This will eventually be solved (content-addressable packages), but that needs reproducibility guarantees that current compilers don’t provide.