Fix print dialog crash on Linux

 # Changelog
 
+## 5.6.8
+
+- Fix print dialog crash on Linux
+
 ## 5.6.7
 
 - Fix imports for Dart 2.15

@@ -105,6 +105,9 @@ static void job_completed(GtkPrintJob* gtk_print_job,
                           gpointer user_data,
                           const GError* error) {
   auto job = static_cast<print_job*>(user_data);
+  if (job->dialog) {
+    gtk_widget_destroy(GTK_WIDGET(job->dialog));
+  }
   on_completed(job, error == nullptr,
                error != nullptr ? error->message : nullptr);
 }
@@ -135,8 +138,7 @@ bool print_job::print_pdf(const gchar* name,
     setup = gtk_page_setup_new();
 
   } else {
-    auto dialog =
-        GTK_PRINT_UNIX_DIALOG(gtk_print_unix_dialog_new(name, nullptr));
+    dialog = GTK_PRINT_UNIX_DIALOG(gtk_print_unix_dialog_new(name, nullptr));
     gtk_print_unix_dialog_set_manual_capabilities(
         dialog, (GtkPrintCapabilities)(GTK_PRINT_CAPABILITY_GENERATE_PDF));
     gtk_print_unix_dialog_set_embed_page_setup(dialog, true);
@@ -157,7 +159,7 @@ bool print_job::print_pdf(const gchar* name,
               gtk_print_unix_dialog_get_settings(GTK_PRINT_UNIX_DIALOG(dialog));
           setup = gtk_print_unix_dialog_get_page_setup(
               GTK_PRINT_UNIX_DIALOG(dialog));
-          gtk_widget_destroy(GTK_WIDGET(dialog));
+          gtk_widget_hide(GTK_WIDGET(dialog));
           loop = false;
         } break;
         case GTK_RESPONSE_APPLY:  // Preview

@@ -31,6 +31,8 @@ class print_job {
   GtkPrintJob* printJob;
 
  public:
+  GtkPrintUnixDialog* dialog = nullptr;
+
   print_job(int index);
 
   ~print_job();

@@ -6,7 +6,7 @@ description: >
 homepage: https://github.com/DavBfr/dart_pdf/tree/master/printing
 repository: https://github.com/DavBfr/dart_pdf
 issue_tracker: https://github.com/DavBfr/dart_pdf/issues
-version: 5.6.7
+version: 5.6.8
 
 environment:
   sdk: ">=2.12.0 <3.0.0"