Disable demo partially.

The demo fails due to the fact we schedule the hessians recursively. This seems
hard to debug because it happens on clang release builds and clad for runtime11,
runtime10, and in some cases runtime9.

More information: https://github.com/vgvassilev/clad/actions/runs/8216311966

demos/Arrays.cpp

@@ -76,13 +76,13 @@ int main() {
   // the indexes of the array by using the format arr[0:<last index of arr>]
   auto hessian_all = clad::hessian(weighted_avg, "arr[0:2], weights[0:2]");
   // Generates the Hessian matrix for weighted_avg w.r.t. to arr.
-  auto hessian_arr = clad::hessian(weighted_avg, "arr[0:2]");
+  // auto hessian_arr = clad::hessian(weighted_avg, "arr[0:2]");
 
   double matrix_all[36] = {0};
-  double matrix_arr[9] = {0};
+  // double matrix_arr[9] = {0};
 
   clad::array_ref<double> matrix_all_ref(matrix_all, 36);
-  clad::array_ref<double> matrix_arr_ref(matrix_arr, 9);
+  // clad::array_ref<double> matrix_arr_ref(matrix_arr, 9);
 
   hessian_all.execute(arr, weights, matrix_all_ref);
   printf("Hessian Mode w.r.t. to all:\n matrix =\n"
@@ -102,12 +102,13 @@ int main() {
          matrix_all[28], matrix_all[29], matrix_all[30], matrix_all[31],
          matrix_all[32], matrix_all[33], matrix_all[34], matrix_all[35]);
 
-  hessian_arr.execute(arr, weights, matrix_arr_ref);
+  /*hessian_arr.execute(arr, weights, matrix_arr_ref);
   printf("Hessian Mode w.r.t. to arr:\n matrix =\n"
          "  {%.2g, %.2g, %.2g}\n"
          "  {%.2g, %.2g, %.2g}\n"
          "  {%.2g, %.2g, %.2g}\n",
          matrix_arr[0], matrix_arr[1], matrix_arr[2], matrix_arr[3],
          matrix_arr[4], matrix_arr[5], matrix_arr[6], matrix_arr[7],
          matrix_arr[8]);
+  */
 }

test/Misc/RunDemos.C

@@ -301,11 +301,11 @@
 // CHECK_ARRAYS_EXEC:   {0.33, 0, 0, 0, 0, 0}
 // CHECK_ARRAYS_EXEC:   {0, 0.33, 0, 0, 0, 0}
 // CHECK_ARRAYS_EXEC:   {0, 0, 0.33, 0, 0, 0}
-// CHECK_ARRAYS_EXEC: Hessian Mode w.r.t. to arr:
-// CHECK_ARRAYS_EXEC:  matrix =
-// CHECK_ARRAYS_EXEC:   {0, 0, 0}
-// CHECK_ARRAYS_EXEC:   {0, 0, 0}
-// CHECK_ARRAYS_EXEC:   {0, 0, 0}
+// CHECK_ARRAYS_EXEC_XFAIL: Hessian Mode w.r.t. to arr:
+// CHECK_ARRAYS_EXEC_XFAIL:  matrix =
+// CHECK_ARRAYS_EXEC_XFAIL:   {0, 0, 0}
+// CHECK_ARRAYS_EXEC_XFAIL:   {0, 0, 0}
+// CHECK_ARRAYS_EXEC_XFAIL:   {0, 0, 0}
 
 //-----------------------------------------------------------------------------/
 // Demo: VectorForwardMode.cpp