Barf on ignored config text

barf.patch

diff --git a/nixos/machines/uberwald/configuration.nix b/nixos/machines/uberwald/configuration.nix
index d276df1..f59e631 100644
--- a/nixos/machines/uberwald/configuration.nix
+++ b/nixos/machines/uberwald/configuration.nix
@@ -1,30 +1,55 @@
 # Edit this configuration file to define what should be installed on
 # your system.  Help is available in the configuration.nix(5) man page
 # and in the NixOS manual (accessible by running ‘nixos-help’).
 
-{ config, pkgs, ... }:
+{ config, pkgs, lib, ... }:
+with lib;
 
 let
   cfg = config.custom;
 in {
   imports =
     [ # Include the results of the hardware scan.
       ./hardware-configuration.nix
       ../../common/fonts.nix
       ../../common/screencast.nix
       ../../common/sound.nix
       ../../common/bluetooth.nix
       ../../common/ssh.nix
       ../../common/epson.nix
+      (
+        # define a new module
+        {config, lib, ...}:
+        {
+          # that defines extra features for the existing config `environment.etc`
+          options.environment.etc = mkOption {
+            type = types.attrsOf (
+              # by the means of an extra submodule type
+              types.submodule (
+                { name, config, ... }:
+                {
+                  # where `source` is assigned with normal priority
+                  config.source = mkIf (config.text != null) (
+                    let name' = "etc-" + baseNameOf name;
+                    in pkgs.writeText name' config.text
+                  );
+                }
+              )
+            );
+          };
+        }
+      )
     ];
 
+  environment.etc.bashrc.source = pkgs.writeText "hacky-bashrc" "Silently override careful bash config";
+
   security.pam.loginLimits = [
     {
       domain = "*";
       item = "nofile";
       type = "soft";
       value = "unlimited";
     }
   ];