So a dev shell as consumed by a flake is typically just a derivation. And typically the most important thing in that derivation is ‘buildInputs’, which is just a list of ‘pkgs.thingIWant’. It’s not uncommon to hook other “phases” of the derivation, which are (oversimplified) just little shell scripts that run in some order (‘configurePhase’ before ‘installPhase’) and typically expressed using the nifty “” syntax. For example if Nix is like stuffing paths into a Makefile that you want to use in your dev shell, you might put that in installPhase. Protip: a Nix “package” (derivation) evaluated in a string context (foo = “${pkgs.gcc}”;) gives you a path to where the thing lives in /nix/store.
Ask your questions on discourse.nixos.org please - the documentation situation in Nix-land is generally exactly as you have noted, which means centralised question-asking in well-known locations is much much more helpful for Those Who Come After.
Agree. I feel the same way about OCaml, and I have forced myself to ask every questions I have on SO to build the list of answers there. Yet, people tend to answer on SO with “you should ask on the OCaml discourse”…