basic system.toplevel with etc files

config.nix

@@ -0,0 +1,114 @@
+{ pkgs }:
+
+let
+
+  eval = pkgs.lib.evalModules
+    { check = true;
+      args = { pkgs = import <nixpkgs> {}; };
+      modules =
+        [ config
+          ./modules/system.nix
+          <nixpkgs/nixos/modules/system/etc/etc.nix>
+        ];
+    };
+
+  config =
+    {
+      system.build.path = pkgs.buildEnv {
+        name = "system-path";
+        paths =
+          [ pkgs.lnl.vim
+            pkgs.curl
+            pkgs.fzf
+            pkgs.gettext
+            pkgs.git
+            pkgs.jq
+            pkgs.silver-searcher
+            pkgs.tmux
+
+            pkgs.nix-prefetch-scripts
+            pkgs.nix-repl
+            pkgs.nox
+          ];
+      };
+
+      environment.etc."profile".text = ''
+        export HOMEBREW_CASK_OPTS="--appdir=/Applications/cask"
+
+        conf=$HOME/src/nixpkgs-config
+        pkgs=$HOME/.nix-defexpr/nixpkgs
+
+        alias ls="ls -G"
+        alias l="ls -hl"
+      '';
+
+      environment.etc."tmux.conf".text = ''
+        set -g default-command "reattach-to-user-namespace -l $SHELL"
+        set -g default-terminal "screen-256color"
+        set -g status-bg black
+        set -g status-fg white
+
+        set -g base-index 1
+        set -g renumber-windows on
+
+        bind c new-window -c '#{pane_current_path}'
+        bind % split-window -v -c '#{pane_current_path}'
+        bind " split-window -h -c '#{pane_current_path}'
+      '';
+
+      environment.etc."zshrc".text = ''
+        autoload -U compinit && compinit
+        autoload -U promptinit && promptinit
+
+        setopt autocd
+
+        export PROMPT='%B%(?..[%?] )%b> '
+        export RPROMPT='%F{green}%~%f'
+
+        export SSL_CERT_FILE=/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt
+        export GIT_SSL_CAINFO=/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt
+
+        export PATH=/nix/var/nix/profiles/default/bin:/nix/var/nix/profiles/default/sbin''${PATH:+:$PATH}
+        export PATH=$HOME/.nix-profile/bin:$HOME/.nix-profile/bin''${PATH:+:$PATH}
+
+        export NIX_PATH=nixpkgs=$HOME/.nix-defexpr/nixpkgs
+        export NIX_REMOTE=daemon
+
+        nixdarwin-rebuild () {
+          case $1 in
+            'switch') nix-env -iA nixpkgs.nixdarwin.toplevel ;;
+            ''')      return 1 ;;
+          esac
+        }
+      '';
+    };
+
+
+in {
+  packageOverrides = self: {
+
+    nixdarwin = eval.config.system.build;
+
+    lnl.vim = pkgs.vim_configurable.customize {
+      name = "vim";
+      vimrcConfig.customRC = ''
+        set nocompatible
+        filetype plugin indent on
+        syntax on
+
+        colorscheme solarized
+        set bg=dark
+
+        set et sw=2 ts=2
+        set bs=indent,start
+
+        set list
+        set listchars=tab:»·,trail:·,extends:⟩,precedes:⟨
+      '';
+      vimrcConfig.vam.pluginDictionaries = [
+        { names = [ "fzfWrapper" "youcompleteme" "surround" "vim-nix" "colors-solarized" ]; }
+      ];
+    };
+
+  };
+}

modules/system.nix

@@ -0,0 +1,35 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.system;
+
+in {
+  options = {
+
+    system.build = mkOption {
+      internal = true;
+      default = {};
+      description = ''
+        Attribute set of derivation used to setup the system.
+      '';
+    };
+
+    system.activationScripts = mkOption {
+      internal = true;
+      default = {};
+    };
+
+  };
+
+  config = {
+
+    system.build.toplevel = pkgs.buildEnv {
+      name = "nixdarwin-system";
+      paths = [ cfg.build.path cfg.build.etc ];
+    };
+
+  };
+}