My understanding is that you should be using shell.nix for your dev environment, and default.nix if you want to actually build the final "nix-package". I have a

My understanding is that you should be using shell.nix for your dev environment, and default.nix if you want to actually build the final "nix-package". I have a gist that talks about this along with python and other language environments: https://gist.github.com/CMCDragonkai/dcc1b538352624ea690d695ee1ff1528 https://gist.github.com/CMCDragonkai/dcc1b538352624ea690d695... However it's not finished, there are some things that still need work. However package/input isolation is not the only isolation you need sometimes (for example, network isolation, fs isolation...etc). When you do need this, Docker provides all these, but it's not compositional. There's a discussion on the Nix issues about this (potentially working towards a new nix-shell development environment can can compose different kinds of isolation): https://github.com/NixOS/nix/issues/903#issuecomment-364744764 https://github.com/NixOS/nix/issues/903#issuecomment-3647447...