Nix shell envs for different purposes.

Usage (example for the test devshell, see flake outputs):

nix develop github:ppenguin/nixenvs#test

or better yet, with direnv, in .envrc:

#!/usr/bin/env bash
use flake "github:ppenguin/nixenvs#test" --impure

You could do without --impure, but some shells rely on <unstable> being pulled from your env (i.e. your NIX_PATH=...:unstable=...). While this is not hermetic, it will cost you less traffic and disk-space.

Of course you can also add an unstable input to the flake.

While it's easiest to just fork and adapt to your needs, I'd be happy to take pull requests for your generic extensions. I.e. any "not-too-specific" things that might benefit others and likely work on most other systems.