implement 12231, --xfail-tb

src/_pytest/terminal.py

@@ -1090,8 +1090,7 @@ class TerminalReporter:
         self, which_reports: str, sep_title: str, needed_opt: Optional[str] = None, style = None
     ) -> None:
         if style is None:
-            style == self.config.option.tbstyle
-
+            style = self.config.option.tbstyle
         if style != "no":
             if not needed_opt or self.hasopt(needed_opt):
                 reports: List[BaseReport] = self.getreports(which_reports)

testing/test_terminal.py

@@ -2949,7 +2949,7 @@ def test_xfail_tb_line(pytester: Pytester) -> None:
             assert a == b
         """
     )
-    result = pytester.runpytest("-rx", "--tb=line")
+    result = pytester.runpytest("-rx", "--xfail-tb=line")
     result.stdout.fnmatch_lines(
         [
             "*= XFAILURES =*",