NixOS packages are not upgrading even though I am certainly configured to 'unstable' system state

[enoren5]

I appreciate your patience and the careful thought you have put in these responses.

I have tried both sets of commands. They both show different errors and a flakes issue persists. Here they are:

First suggestion

$ sudo -i

# export NIX_PATH=nixpkgs=/nix/var/nix/profiles/per-user/root/channels 
nixos-rebuild switch --upgrade-all   
unpacking 1 channels...
unpacking 1 channels...
error: attribute 'system' missing
       at «string»:1:33:
            1| with import <nixpkgs/nixos> {}; config.system.build.nixos-rebuild
             |                                 ^
building Nix...
error: attribute 'nix' in selection path 'config.nix.package.out' not found
error: opening file '/nix/store/bjr17hv9r2fqk5g13wm8ij5rlddgl5ny-user-environment/default.nix': No such file or directory
error: file 'nixpkgs/nixos/modules/installer/tools/nix-fallback-paths.nix' was not found in the Nix search path (add it using $NIX_PATH or -I)
/tmp/nixos-rebuild.CHQkKS/nix
building the system configuration...
error: expression does not evaluate to a derivation (or a set or list of those)
#

Second suggestion

$ sudo NIX_PATH=nixpkgs=/nix/var/nix/profiles/per-user/root/channels nixos-rebuild switch --upgrade-all
unpacking 1 channels...
unpacking 1 channels...
error:
       … while calling the 'import' builtin
         at «string»:1:6:
            1| with import <nixpkgs/nixos> {}; config.system.build.nixos-rebuild
             |      ^

       … while realising the context of a path

       … while calling the 'findFile' builtin
         at «string»:1:13:
            1| with import <nixpkgs/nixos> {}; config.system.build.nixos-rebuild
             |             ^

       error: experimental Nix feature 'flakes' is disabled; add '--extra-experimental-features flakes' to enable it
building Nix...
error: experimental Nix feature 'flakes' is disabled; add '--extra-experimental-features flakes' to enable it
error: experimental Nix feature 'flakes' is disabled; add '--extra-experimental-features flakes' to enable it
error: experimental Nix feature 'flakes' is disabled; add '--extra-experimental-features flakes' to enable it
/tmp/nixos-rebuild.FtUBIg/nix
error: experimental Nix feature 'flakes' is disabled; add '--extra-experimental-features flakes' to enable it
building the system configuration...
error: experimental Nix feature 'flakes' is disabled; add '--extra-experimental-features flakes' to enable it
$

@Torinthiel

The reason setting environment.variables in configuration.nix didn’t work is that it would only take effect after you rebuilt. But please remove it, it’ll conflict with what nixos is doing by default. And while it would work for now, it’d probably hit you when you’ve forgotten about it (like your stray flake files in the first place).

Noted. I made the change to my configuration.nix but stashed the changes effectively removing those lines.

It’s bed time for me too now. I will be back tomorrow when I can. Hopefully you @Torinthiel or another forum member can jump in here and advise on some things we can try next.