Fix shell.nix by pinning nixpkgs

shell.nix

@@ -1,17 +1,33 @@
-# dfu-programmer doesn't have darwin on it's list of supported platforms
-{ pkgs ? import <nixpkgs> { config = { allowUnsupportedSystem = true; }; }
-, avr ? true, arm ? true, teensy ? true }:
+{ avr ? true, arm ? true, teensy ? true }:
 
-with pkgs;
 let
- avrbinutils = pkgsCross.avr.buildPackages.binutils;
- avrlibc = pkgsCross.avr.libcCross;
- gcc-arm-embedded = (import (builtins.fetchTarball {
- url = "https://github.com/NixOS/nixpkgs-channels/archive/87f146a41c463a64c93022b11cf19716b3a22037.tar.gz";
- sha256 = "0rk8haf19plw6vyvq0am99rik0hrrysknjw0f2vs7985awngy3q2";
- }) {}).gcc-arm-embedded;
+ overlay = self: super:
+ let addDarwinSupport = pkg: pkg.overrideAttrs (oldAttrs: {
+ meta.platforms = (oldAttrs.meta.platforms or []) ++ self.lib.platforms.darwin;
+ });
+ in {
+ dfu-programmer = addDarwinSupport super.dfu-programmer;
+ teensy-loader-cli = addDarwinSupport super.teensy-loader-cli;
+
+ avrgcc = super.avrgcc.overrideAttrs (oldAttrs: rec {
+ name = "avr-gcc-8.1.0";
+ src = super.fetchurl {
+ url = "mirror:https://gcc/releases/gcc-8.1.0/gcc-8.1.0.tar.xz";
+ sha256 = "0lxil8x0jjx7zbf90cy1rli650akaa6hpk8wk8s62vk2jbwnc60x";
+ };
+ });
+ };
 
- avr_incflags = [
+ nixpkgs = builtins.fetchTarball {
+ url = "https://github.com/NixOS/nixpkgs/archive/0260747427737b980f0.tar.gz";
+ sha256 = "1p2yc6b40xvvxvmlqd9wb440pkrimnlc2wsbpa5rddlpx1dn8qmf";
+ };
+
+ pkgs = import nixpkgs { overlays = [ overlay ]; };
+in
+
+with pkgs;
+let avr_incflags = [
  "-isystem ${avrlibc}/avr/include"
  "-B${avrlibc}/avr/lib/avr5"
  "-L${avrlibc}/avr/lib/avr5"
@@ -20,15 +36,7 @@ let
  "-B${avrlibc}/avr/lib/avr51"
  "-L${avrlibc}/avr/lib/avr51"
  ];
- avrgcc = pkgsCross.avr.buildPackages.gcc.overrideAttrs (oldAttrs: rec {
- name = "avr-gcc-8.1.0";
- src = fetchurl {
- url = "mirror:https://gcc/releases/gcc-8.1.0/gcc-8.1.0.tar.xz";
- sha256 = "0lxil8x0jjx7zbf90cy1rli650akaa6hpk8wk8s62vk2jbwnc60x";
- };
- });
 in
-
 stdenv.mkDerivation {
  name = "qmk-firmware";