https://github.com/shopkeep/pytest-black/issues/70

--- jaraco.env-1.0.0/setup.cfg.orig
+++ jaraco.env-1.0.0/setup.cfg
@@ -29,8 +29,6 @@
 testing = 
 	pytest >= 6
 	pytest-checkdocs >= 2.4
-	pytest-black >= 0.3.7; \
-	python_implementation != "PyPy"
 	pytest-cov
 	pytest-mypy >= 0.9.1; \
 	python_implementation != "PyPy"