Freeze black to 19.10b0 version

Black fails with "I/O operation on closed file", see the reported issue on black: psf/black#1664
enzbang · Sep 2, 2020 · b07c7a7 · b07c7a7
1 parent d81ee88
commit b07c7a7
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/tox.ini b/tox.ini
@@ -32,7 +32,7 @@ commands=
 # Use latest supported version of Python to run the style checks
 basepython = python3.8
 deps =
-      black
+      black==19.10b0
       mypy
       flake8
       flake8-bugbear