👷 Updated error handling (#348)

src/app.py

@@ -152,7 +152,8 @@ class APP(object):
                 try:
                     self.resource[resource_name] = future.result()
                 except BuilderError as e:
-                    raise PatchingFailedError(e) from e
+                    msg = "Failed to download resource."
+                    raise PatchingFailedError(msg) from e
 
     @staticmethod
     def generate_filename(url: str) -> str:

src/exceptions.py

@@ -7,6 +7,11 @@ class BuilderError(Exception):
 
     message = "Default Error message."
 
+    def __init__(self: Self, *args: Any, **kwargs: Any) -> None:
+        if args:
+            self.message = args[0]
+        super().__init__(self.message)
+
     def __str__(self: Self) -> str:
         """Return error message."""
         return self.message