Package in Nix package manager broken

``` gpt-cli version: 0.4.1 programs: gpt description: Command-line interface for ChatGPT, Claude and Bard homepage: https://github.com/kharvd/gpt-cli license: MIT License ``` This is unfortunately broken. Though, I was able to install it using pipx, which wasn't mentioned in the installation tutorial. The short error message probably won't help much, the point is just that it doesn't work: ``` … while evaluating the option `users.users.user.packages': … while evaluating definitions from `/etc/nixos/configuration.nix': (stack trace truncated; use '--show-trace' to show the full, detailed trace) error: undefined variable 'gpt-cli' ``` Partially related (backlink): https://discourse.nixos.org/t/packages-of-gpt-cli-and-gpt-box-dont-install/65503/