fix.

Author: tobiasraabe

src/_pytask/debugging.py

@@ -67,6 +67,8 @@ def _parse_pdbcls(value: str | None) -> tuple[str, str] | None:
     if not isinstance(value, str):
         msg = "'pdbcls' must be a string in format 'module:classname'"
         raise TypeError(msg)
+    if isinstance(value, tuple) and len(value) == 2:  # noqa: PLR2004
+        return value
     split = value.split(":")
     if len(split) != 2:  # noqa: PLR2004
         msg = (