I’m new to NixOS and like it so far, but one thing I keep missing is a progress bar when installing and updating packages. My internet connection can be very slow at times, so it would be nice to know what it’s doing, whether it’s stuck on a slow download at a few kB/s or compiling a large package.
nixos-rebuild is not very complicated. You can build your system manually with nix-build '<nixpkgs/nixos>' -A system --log-format bar-with-logs and then switch to it with sudo ./result/bin/switch-to-configuration switch.