‘nix-shell’ has two purposes: opening a shell to use packages (e.g. nix-shell -p hello, producing a shell where hello is available), and opening a shell to build a project interactively (e.g. nix-shell '<nixpkgs>' -A hello, producing a shell where e.g. buildPhase is available to build hello).
This post is about using nix-shell to use packages, not build them. I often use shell.nix to store exactly the environment needed to work with a certain project. For example, when I work on akka (which is not packaged for Nix and I’m not sure that would make sense), I use the following shell.nix:
{ pkgs ? import <nixpkgs> {} }:
pkgs.mkShell {
name = "akka";
buildInputs = [
(pkgs.sbt.override {
jre = pkgs.jdk11;
})
pkgs.graphviz
pkgs.multimarkdown
pkgs.diffoscope
];
JAVA_8_HOME = "${pkgs.jdk8}/lib/openjdk";
JAVA_11_HOME = "${pkgs.jdk11}/lib/openjdk";
}
This works great, however, with the new nix commands and Flakes being the New Hotness I wanted to try that out. If I understand correctly, the Flakes equivalent of “nix-shell for using packages” is nix shell, where the equivalent for “nix-shell for building packages interactively” is nix develop - so it sounds like I want nix shell.
How do I store my desired shell in a flake? nix shell --help only seems to show examples of using nix shell specifying the packages on the command line.
(I know I could populate devShell and use nix develop, but that seems like going against the grain: for example, nix shell will use my favorite shell while nix develop, for reasonable reasons, uses bash. I could also just save the nix shell invocation in some script, but that’d get uncomfortable for environments with more tweaks/overrides/etc)
