https://nixos.wiki/wiki/Nix_Expression_Language

2020
Tropin - Nix syntax basics
    https://www.youtube.com/watch?v=5F-1Q3nk4Es
    ! need to look
    https://github.com/abcdw/rde
    https://gist.github.com/abcdw/8b29ee06c05c43369e27de183a71449d