diff -Naur grpc-1.37.0-original/tools/distrib/python/grpcio_tools/grpc_tools/protoc.py grpc-1.37.0/tools/distrib/python/grpcio_tools/grpc_tools/protoc.py

--- grpc-1.37.0-original/tools/distrib/python/grpcio_tools/grpc_tools/protoc.py	2021-04-06 18:48:56.000000000 -0400

+++ grpc-1.37.0/tools/distrib/python/grpcio_tools/grpc_tools/protoc.py	2021-04-22 15:45:59.234743676 -0400

@@ -42,6 +42,7 @@

 if sys.version_info >= (3, 5, 0):

     import contextlib

     import importlib

+    import importlib.abc

     import importlib.machinery

     import threading