Nixpkgs

nixpkgs crossSystem

• default.nix
  • pkgs/top-level/impure.nix
    • pkgs/top-level/default.nix
      • lib.systems.elaborate crossSystem0;
        • lib/systems/default.nix: elaborate
          • parsed = parse.mkSystemFromString ... args.system; // args.system = crossSystem
            • lib/systems/parse.nix
              • mkSystemFromString = s: mkSystemFromSkeleton (mkSkeletonFromList (lib.splitString "-" s));
                • mkSkeletonFromList

注意mkSkeletonFromList通过 ${toString (length l)} 实现了一个根据l长度的switch case。

crossSystem的4个域分别为cpu-vendor-kernel-abi

import nixpkgs

import <nixpgks> {} 的加载流程

• default.nix
  • pkgs/top-level/impure.nix
    • pkgs/top-level/default.nix
      • stdenvStages import pkgs/stdenv/default.nix
        • stagesLinux = import pkgs/stdenv/linux/
          • thisStdenv, stdenv = import pkgs/stdenv/generic/default.nix
            • import lib/default.nix

              this is where customisation.nix come from

      • allPackages import pkgs/top-level/stage.nix
        • allPackages import pkgs/top-level/all-packages.nix
      • boot = import pkgs/stdenv/booter.nix

vim_configurable.override {python = python3} vimUtils.makeCustomizable (vim.override {python = python3}) vimUtils.makeCustomizable (vim.override {python = python3})

似乎是一个浮现override变量的最小集 f = a:{res = a+1;} fo = pkgsMiao.makeOverride f f 2