Add workaround for python/mypy#8627. Fixes #18.

jaraco · jaraco · commit c4e3b4d7bac2 · 2020-05-23T11:53:35.000-04:00
diff --git a/setup.cfg b/setup.cfg
@@ -29,6 +29,8 @@ testing =
 	pytest-black >= 0.3.7
 	pytest-cov
 	pytest-mypy
+	# workaround for python/mypy#8627
+	mypy@git+https://github.com/python/mypy
 
 	# local
 
