FileSystemLoader includes search paths in error

CHANGES.rst

@@ -35,6 +35,8 @@ Unreleased
 -   Fix `copy`/`pickle` support for the internal ``missing`` object.
     :issue:`2027`
 -   ``Environment.overlay(enable_async)`` is applied correctly. :pr:`2061`
+-   Paths where the loader searched for the template were added
+    to the error message. :issue:`1661`
 
 
 Version 3.1.4

src/jinja2/loaders.py

@@ -204,7 +204,10 @@ class FileSystemLoader(BaseLoader):
             if os.path.isfile(filename):
                 break
         else:
-            raise TemplateNotFound(template)
+            raise TemplateNotFound(
+                f"{template} not found in the following search path(s):"
+                f" {self.searchpath}"
+            )
 
         with open(filename, encoding=self.encoding) as f:
             contents = f.read()