Check in the fact that importlib.machinery.PathFinder now exists.
diff --git a/Lib/importlib/machinery.py b/Lib/importlib/machinery.py
index 40d39f4..5197744 100644
--- a/Lib/importlib/machinery.py
+++ b/Lib/importlib/machinery.py
@@ -2,3 +2,4 @@
 
 from ._bootstrap import BuiltinImporter
 from ._bootstrap import FrozenImporter
+from ._bootstrap import PathFinder