Also doing C dev on cranberry

cranberry/features.nix

@@ -3,7 +3,10 @@
   config = {
     frogeye = {
       desktop.xorg = true;
-      dev.vm = true;
+      dev = {
+        c = true;
+        vm = true;
+      };
       extra = true;
     };
   };

os/desktop/default.nix

@@ -41,9 +41,11 @@
             languages = [ "fr" ];
             symbolsFile = "${pkgs.stdenv.mkDerivation {
               name = "qwerty-fr-keypad";
-              src = builtins.fetchGit {
-                url = "https://github.com/qwerty-fr/qwerty-fr.git";
+              src = pkgs.fetchFromGitHub {
+                owner = "qwerty-fr";
+                repo = "qwerty-fr";
                 rev = "3a4d13089e8ef016aa20baf6b2bf3ea53de674b8";
+                sha256 = "sha256-wn5n6jJVDrQWJze8xYF2nEY8a7mHI3hVO4xsT4LMo9c=";
               };
               patches = [ ./qwerty-fr-keypad.diff ];
               # TODO This doesn't seem to be applied... it's the whole point of the derivation :(