cross: fix emulateBuilder to use build bash in the vmRunCommand

overlays/cross.nix

@@ -718,11 +718,7 @@ in {
   };
   koreader = (prev.koreader.override {
     # fixes runtime error: luajit: ./ffi/util.lua:757: attempt to call field 'pack' (a nil value)
-    # inherit (emulated) luajit;
-    luajit = final.luajit.override {
-      inherit (emulated) stdenv;
-      buildPackages.stdenv = emulated.stdenv;  # it uses buildPackages.stdenv for HOST_CC
-    };
+    inherit (emulated) luajit;
   }).overrideAttrs (upstream: {
     nativeBuildInputs = upstream.nativeBuildInputs ++ [
       final.autoPatchelfHook
@@ -730,11 +726,7 @@ in {
   });
   koreader-from-src = prev.koreader-from-src.override {
     # fixes runtime error: luajit: ./ffi/util.lua:757: attempt to call field 'pack' (a nil value)
-    # inherit (emulated) luajit;
-    luajit = final.luajit.override {
-      inherit (emulated) stdenv;
-      buildPackages.stdenv = emulated.stdenv;  # it uses buildPackages.stdenv for HOST_CC
-    };
+    inherit (emulated) luajit;
   };
   # libgweather = rmNativeInputs [ final.glib ] (prev.libgweather.override {
   #   # alternative to emulating python3 is to specify it in `buildInputs` instead of `nativeBuildInputs` (upstream),