ValueError: path is on mount 'S:', start on mount 'C:'
On Windows 10, using SublimeLinter 4, I have some symlinks from within my home at `C:\\Users\\bmix` to `S:\\Users\\bmix`. I occasionally get the following error. What does it mean?

> Traceback (most recent call last):
>   File "lint.events in C:\\Users\\bmix\\AppData\\Roaming\\Sublime Text 3\\Installed Packages\\SublimeLinter.sublime-package", line 28, in broadcast
>   File "panel_view in C:\\Users\\bmix\\AppData\\Roaming\\Sublime Text 3\\Installed Packages\\SublimeLinter.sublime-package", line 48, in on_lint_result
>   File "panel_view in C:\\Users\\bmix\\AppData\\Roaming\\Sublime Text 3\\Installed Packages\\SublimeLinter.sublime-package", line 277, in fill_panel
>   File "panel_view in C:\\Users\\bmix\\AppData\\Roaming\\Sublime Text 3\\Installed Packages\\SublimeLinter.sublime-package", line 166, in create_path_dict
>   File "panel_view in C:\\Users\\bmix\\AppData\\Roaming\\Sublime Text 3\\Installed Packages\\SublimeLinter.sublime-package", line 166, in <dictcomp>
>   File "./python3.3/ntpath.py", line 564, in relpath
> ValueError: path is on mount 'S:', start on mount 'C:'
diff --git a/panel_view.py b/panel_view.py
index 70f6c82..7b8cb87 100644
--- a/panel_view.py
+++ b/panel_view.py
@@ -159,9 +159,9 @@ def create_path_dict(window, bids):
 
     rel_paths = {
         bid: (
-            abs_path
-            if abs_path.startswith('<untitled')
-            else os.path.relpath(abs_path, base_dir)
+            os.path.relpath(abs_path, base_dir)
+            if base_dir and not abs_path.startswith('<untitled')
+            else abs_path
         )
         for bid, abs_path in file_names_by_bid.items()
     }
['panel_view.py']