Merge master into features

Several conflicts, mostly due to 2c402f4bd.

Conflicts:
	.pre-commit-config.yaml
	src/_pytest/outcomes.py
	src/_pytest/python_api.py
	tox.ini

1 files changed, 6 insertions, 0 deletions

diff --git a/src/_pytest/outcomes.py b/src/_pytest/outcomes.py
index a5a4e655b..5e331a323 100644
--- a/src/_pytest/outcomes.py
+++ b/src/_pytest/outcomes.py
@@ -18,6 +18,12 @@ class OutcomeException(BaseException):
     """
 
     def __init__(self, msg: Optional[str] = None, pytrace: bool = True) -> None:
+        if msg is not None and not isinstance(msg, str):
+            error_msg = (
+                "{} expected string as 'msg' parameter, got '{}' instead.\n"
+                "Perhaps you meant to use a mark?"
+            )
+            raise TypeError(error_msg.format(type(self).__name__, type(msg).__name__))
         BaseException.__init__(self, msg)
         self.msg = msg
         self.pytrace = pytrace