Merge pull request #4283 from matrix-org/erikj/isort_df

Make isort tox check print diff when it fails

changelog.d/4283.misc

+Make isort tox check print diff when it fails

tox.ini

@@ -134,7 +134,7 @@ commands = /bin/sh -c "flake8 synapse tests scripts scripts-dev scripts/hash_pas
 [testenv:check_isort]
 skip_install = True
 deps = isort
-commands = /bin/sh -c "isort -c -sp setup.cfg -rc synapse tests"
+commands = /bin/sh -c "isort -c -df -sp setup.cfg -rc synapse tests"
 
 [testenv:check-newsfragment]
 skip_install = True
@@ -150,4 +150,4 @@ deps =
     codecov
 commands =
     coverage combine
-    codecov -X gcov
\ No newline at end of file
+    codecov -X gcov