openocd VS haskell-te

I also really like flakes. I know they are still experimental today - though hopefully that'll improve with this RFC - but they make it trivial to have an out of tree package. For example I just recently created a flake for a vendor OpenOCD fork [0] - and now I can reference that in my home-manager config or from some other project.

[0] - https://github.com/benpye/openocd/blob/mrs-2023-08-07/defaul...

Yes, to get Nixpkgs it's much faster to use `fetchTarball`.

You're right that `builtins.fetchTarball` is faster than `builtins.fetchGit` (due to the ridiculous amount of commits in the Nixpkgs repo). I like to keep such definitions in a single, company-wide/project-agnostic git repo (what the Nix Pills series calls the "repository pattern"), and have individual projects import them via `builtins.fetchGit`.

Many years ago we didn't have `builtins.fetchGit`, so had to use the 'fetchgit' function from Nixpkgs instead. That created a chicken-and-egg situation if we wanted to take the Nixpkgs version from some other git repo; hence needing to "bootstrap" via `(import { config = {}; }).fetchgit`, and cross our fingers that `NIX_PATH` wasn't set to some crazy value (which, of course, I would inevitably do... https://github.com/Warbo/haskell-te/blob/24475a229908caa3447... )

Note that we need `config = {};` when importing Nixpkgs to avoid an impurity which tries to read files in $HOME. More recent versions of Nixpkgs also need `overlays = [];` to avoid another impurity (looks like this changed at Nixpkgs 17.03, according to https://github.com/Warbo/nix-helpers/blob/master/nixpkgs.nix )