dreamchess: fix default engine propagation

pkgs/by-name/dr/dreamchess/package.nix

@@ -6,6 +6,7 @@
   bison,
   flex,
   gettext,
+  makeWrapper,
   SDL2,
   SDL2_image,
   SDL2_mixer,
@@ -48,6 +49,7 @@ stdenv.mkDerivation (finalAttrs: {
     bison
     flex
     gettext
+    makeWrapper
   ];
   cmakeFlags = [
     (lib.cmakeBool "CMAKE_VERBOSE_MAKEFILE" true)
@@ -55,10 +57,18 @@ stdenv.mkDerivation (finalAttrs: {
     (lib.cmakeFeature "CMAKE_INSTALL_DATAROOTDIR" "${placeholder "out"}/share")
   ];
 
+  # This makes sure the default engine (dreamer) will be called from
+  # the /nix/store/ as well when starting a new game
+  postFixup = ''
+    wrapProgram $out/bin/dreamchess \
+      --prefix PATH : $out/bin
+  '';
+
   doInstallCheck = true;
 
   postInstallCheck = ''
     stat "''${!outputBin}/bin/${finalAttrs.meta.mainProgram}"
+    stat "''${!outputBin}/bin/dreamer"
   '';
 
   meta = {