Path.is_related_to is only in python 3.9 so changing to related_to me…

…thod to be compatible with older python versions

bd-splitter.py

@@ -114,7 +114,17 @@ def in_exclude_list(abs_path):
             # TODO: Need to pop folders from the exclude list as we deal with them. How?
             if subdir not in scan_dirs and subdir not in exclude_folders:
                 logging.debug(f"adding subdir {subdir} to list of directories to scan")
-                exclude_folders_under_subdir = [f for f in exclude_folders if f.is_relative_to(subdir)]
+                exclude_folders_under_subdir = list()
+                for f in exclude_folders:
+                    try:
+                        f.relative_to(subdir)
+                    except ValueError:
+                        logging.debug(f"folder {f} is not a sub-dir of {subdir}")
+                        continue
+                    else:
+                        logging.debug(f"folder {f} is a sub-dir of {subdir} so will exclude it from detect scan of {subdir}")
+                        exclude_folders_under_subdir.append(f)
+                # exclude_folders_under_subdir = [f for f in exclude_folders if f.is_relative_to(subdir)]
                 logging.debug(f"excluding dirs {exclude_folders_under_subdir} from subdir {subdir} analysis")
                 scan_dirs[subdir] = {"exclude_folders": exclude_folders_under_subdir}
                 exclude_folders -= set(exclude_folders_under_subdir)