Try to fix tests

cvat/apps/dataset_manager/cron.py

@@ -103,7 +103,7 @@ def _cleanup(self) -> None:
         #    In that case an exception is expected and is handled by the cron process.
         # 2. A temporary file/directory can be removed by the cron job only when it is outdated.
         # 3. Each temporary file/directory has a unique name, so the race condition when one process is creating an object
-        # and another is removing it - impossible.
+        #    and another is removing it - impossible.
         for child in os.scandir(TmpDirManager.TMP_ROOT):
             # stop clean up process correctly before rq job timeout is ended
             if self._stop_event.is_set():

cvat/apps/dataset_manager/views.py

@@ -169,8 +169,10 @@ def export(
 
         with TmpDirManager.get_tmp_directory_for_export(instance_type=instance_type) as temp_dir:
             temp_file = osp.join(temp_dir, 'result')
+            temp_subdir = osp.join(temp_dir, 'subdir')
+            os.makedirs(temp_subdir, exist_ok=True)
             export_fn(db_instance.id, temp_file, format_name=dst_format,
-                server_url=server_url, save_images=save_images, temp_dir=temp_dir)
+                server_url=server_url, save_images=save_images, temp_dir=temp_subdir)
             with get_export_cache_lock(
                 output_path,
                 ttl=EXPORT_CACHE_LOCK_TTL,

cvat/apps/engine/backup.py

@@ -1202,7 +1202,6 @@ def _import(importer, request, queue, rq_id, Serializer, file_field_name, locati
     return Response(serializer.data, status=status.HTTP_202_ACCEPTED)
 
 def get_backup_dirname():
-    # FUTURE-FIXME
     return TmpDirManager.TMP_ROOT
 
 def import_project(request, queue_name, filename=None):