tests/test-check-format.t

--- a/tests/test-check-format.t	Mon Feb 01 17:13:24 2021 -0500
+++ b/tests/test-check-format.t	Tue Feb 02 15:35:38 2021 +0100
@@ -1,5 +1,5 @@
 #require black test-repo
 
   $ cd $RUNTESTDIR/..
-  $ black --check --diff `hg files 'set:(**.py + grep("^#!.*python")) - mercurial/thirdparty/**'`
+  $ black --config=black.toml --check --diff `hg files 'set:(**.py + grep("^#!.*python")) - mercurial/thirdparty/**'`