nixpkgs/pkgs/os-specific/linux/nixos-rebuild/default.nix
Patryk Wychowaniec 2c55eba8f4
nixos: add --specialisation to nixos-rebuild
This commit fixes a papercut in nixos-rebuild where people wanting to
switch to a specialisation (or test one) were forced to manually figure
out the specialisation's path and run its activation script - since now,
there's a dedicated option to do just that.

This is a backwards-compatible change which doesn't affect the existing
behavior, which - to be fair - might still be considered sus by some
people, the painful scenario here being:

- you boot into specialisation `foo`,
- you run `nixos-rebuild switch`,
- whoops, you're no longer at specialisation `foo`, but you're rather
  brought back to the base system.

(it's especially painful for cases where specialisation is used to load
extra drivers, e.g. Nvidia, since then launching `nixos-rebuild switch`,
while forgetting that you're inside a specialisation, can cause some
parts of your system to get accidentally unloaded.)

I've tried to mitigate that by improving specialisations so that they
create a dedicated file somewhere in `/run/current-system` containing
the specialisation's name (which `nixos-rebuild` could then use as the
default value for `--specialisation`), but I haven't been able to come
up with anything working (plus it would be a breaking change then).

Closes https://github.com/NixOS/nixpkgs/issues/174065
2023-01-15 18:16:49 +01:00

37 lines
1 KiB
Nix

{ substituteAll
, runtimeShell
, coreutils
, gnused
, gnugrep
, nix
, lib
, nixosTests
}:
let
fallback = import ./../../../../nixos/modules/installer/tools/nix-fallback-paths.nix;
in
substituteAll {
name = "nixos-rebuild";
src = ./nixos-rebuild.sh;
dir = "bin";
isExecutable = true;
inherit runtimeShell nix;
nix_x86_64_linux = fallback.x86_64-linux;
nix_i686_linux = fallback.i686-linux;
nix_aarch64_linux = fallback.aarch64-linux;
path = lib.makeBinPath [ coreutils gnused gnugrep ];
# run some a simple installer tests to make sure nixos-rebuild still works for them
passthru.tests = {
simple-installer = nixosTests.installer.simple;
specialisations = nixosTests.nixos-rebuild-specialisations;
};
meta = {
description = "Rebuild your NixOS configuration and switch to it, on local hosts and remote.";
homepage = "https://github.com/NixOS/nixpkgs/tree/master/pkgs/os-specific/linux/nixos-rebuild";
license = lib.licenses.mit;
maintainers = [ lib.maintainers.Profpatsch ];
mainProgram = "nixos-rebuild";
};
}