evilwm: change prePatch to postPatch

pkgs/applications/window-managers/evilwm/default.nix

@@ -26,8 +26,11 @@ stdenv.mkDerivation rec {
     xorgproto
   ];
 
-  prePatch = ''substituteInPlace ./Makefile --replace /usr $out \
-                                            --replace "CC = gcc" "#CC = gcc"'';
+  postPatch = ''
+    substituteInPlace ./Makefile \
+      --replace /usr $out \
+      --replace "CC = gcc" "#CC = gcc"
+  '';
 
   # Allow users set their own list of patches
   inherit patches;
@@ -35,14 +38,12 @@ stdenv.mkDerivation rec {
   meta = with lib; {
     homepage = "http://www.6809.org.uk/evilwm/";
     description = "Minimalist window manager for the X Window System";
-
     license = {
       shortName = "evilwm";
       fullName = "Custom, inherited from aewm and 9wm";
       url = "http://www.6809.org.uk/evilwm/";
       free = true;
     }; # like BSD/MIT, but Share-Alike'y; See README.
-
     maintainers = with maintainers; [ amiloradovsky ];
     platforms = platforms.all;
   };