nixpkgs/doc/builders/special/mkshell.section.md
Jonas Chevalier 1e910209ae
mkShell: make it buildable (#153194)
When I designed `mkShell`, I didn't have a good idea of what the output
should look like and so decided to make the build fail. In practice,
this causes quite a bit of confusion and complications because now the
shell cannot be part of a normal package set without failing the CI as
well.

This commit changes that build phase to record all the build inputs in a
file. That way it becomes possible to build it, makes sure that all the
build inputs get built as well, and also can be used as a GC root.
(by applying the same trick as #95536).

The documentation has also been improved to better describe what mkShell
does and how to use it.
2022-01-08 01:54:04 +01:00

1.1 KiB

pkgs.mkShell

pkgs.mkShell is a specialized stdenv.mkDerivation that removes some repetition when using it with nix-shell (or nix develop).

Usage

Here is a common usage example:

{ pkgs ? import <nixpkgs> {} }:
pkgs.mkShell {
  packages = [ pkgs.gnumake ];

  inputsFrom = [ pkgs.hello pkgs.gnutar ];

  shellHook = ''
    export DEBUG=1
  '';
}

Attributes

  • name (default: nix-shell). Set the name of the derivation.
  • packages (default: []). Add executable packages to the nix-shell environment.
  • inputsFrom (default: []). Add build dependencies of the listed derivations to the nix-shell environment.
  • shellHook (default: ""). Bash statements that are executed by nix-shell.

... all the attributes of stdenv.mkDerivation.

Building the shell

This derivation output will contain a text file that contains a reference to all the build inputs. This is useful in CI where we want to make sure that every derivation, and its dependencies, build properly. Or when creating a GC root so that the build dependencies don't get garbage-collected.