diff --git a/IPython/core/tests/simpleerr.py b/IPython/core/tests/simpleerr.py
index 34e6970..5ba5084 100644
--- a/IPython/core/tests/simpleerr.py
+++ b/IPython/core/tests/simpleerr.py
@@ -8,7 +8,7 @@ def div0():
     x/y
 
 def sysexit(stat, mode):
-    raise SystemExit(stat, 'Mode = %s' % mode)
+    raise SystemExit(stat, f'Mode = {mode}')
 
 def bar(mode):
     "bar"
diff --git a/IPython/core/tests/test_iplib.py b/IPython/core/tests/test_iplib.py
index 6804c2b..0ee1b8d 100644
--- a/IPython/core/tests/test_iplib.py
+++ b/IPython/core/tests/test_iplib.py
@@ -118,91 +118,83 @@ def doctest_tb_verbose():
     """
 
 
-# TODO : Marc 2021 – this seem to fail due
-# to upstream changes in CI for whatever reason.
-# Commenting for now, to revive someday (maybe?)
-# nose won't work in 3.10 anyway and we'll have to disable iptest.
-# thus this likely need to bemigrated to pytest.
-
-
-# def doctest_tb_sysexit():
-#     """
-# In [17]: %xmode plain
-# Exception reporting mode: Plain
-#
-# In [18]: %run simpleerr.py exit
-# An exception has occurred, use %tb to see the full traceback.
-# SystemExit: (1, 'Mode = exit')
-#
-# In [19]: %run simpleerr.py exit 2
-# An exception has occurred, use %tb to see the full traceback.
-# SystemExit: (2, 'Mode = exit')
-#
-# In [20]: %tb
-# Traceback (most recent call last):
-#   File ... in <module>
-#     bar(mode)
-#   File ... line 22, in bar
-#     sysexit(stat, mode)
-#   File ... line 11, in sysexit
-#     raise SystemExit(stat, 'Mode = %s' % mode)
-# SystemExit: (2, 'Mode = exit')
-#
-# In [21]: %xmode context
-# Exception reporting mode: Context
-#
-# In [22]: %tb
-# ---------------------------------------------------------------------------
-# SystemExit                                Traceback (most recent call last)
-# <BLANKLINE>
-# ...<module>
-#      29     except IndexError:
-#      30         mode = 'div'
-# ---> 32     bar(mode)
-# <BLANKLINE>
-# ...bar(mode)
-#      20         except:
-#      21             stat = 1
-# ---> 22         sysexit(stat, mode)
-#      23     else:
-#      24         raise ValueError('Unknown mode')
-# <BLANKLINE>
-# ...sysexit(stat, mode)
-#      10 def sysexit(stat, mode):
-# ---> 11     raise SystemExit(stat, 'Mode = %s' % mode)
-# <BLANKLINE>
-# SystemExit: (2, 'Mode = exit')
-#
-# In [23]: %xmode verbose
-# Exception reporting mode: Verbose
-#
-# In [24]: %tb
-# ---------------------------------------------------------------------------
-# SystemExit                                Traceback (most recent call last)
-# <BLANKLINE>
-# ... in <module>
-#      29     except IndexError:
-#      30         mode = 'div'
-# ---> 32     bar(mode)
-#         mode = 'exit'
-# <BLANKLINE>
-# ... in bar(mode='exit')
-#      20         except:
-#      21             stat = 1
-# ---> 22         sysexit(stat, mode)
-#         mode = 'exit'
-#         stat = 2
-#      23     else:
-#      24         raise ValueError('Unknown mode')
-# <BLANKLINE>
-# ... in sysexit(stat=2, mode='exit')
-#      10 def sysexit(stat, mode):
-# ---> 11     raise SystemExit(stat, 'Mode = %s' % mode)
-#         stat = 2
-#         mode = 'exit'
-# <BLANKLINE>
-# SystemExit: (2, 'Mode = exit')
-#     """
+def doctest_tb_sysexit():
+    """
+    In [17]: %xmode plain
+    Exception reporting mode: Plain
+
+    In [18]: %run simpleerr.py exit
+    An exception has occurred, use %tb to see the full traceback.
+    SystemExit: (1, 'Mode = exit')
+
+    In [19]: %run simpleerr.py exit 2
+    An exception has occurred, use %tb to see the full traceback.
+    SystemExit: (2, 'Mode = exit')
+
+    In [20]: %tb
+    Traceback (most recent call last):
+      File ... in <module>
+        bar(mode)
+      File ... line 22, in bar
+        sysexit(stat, mode)
+      File ... line 11, in sysexit
+        raise SystemExit(stat, f'Mode = {mode}')
+    SystemExit: (2, 'Mode = exit')
+
+    In [21]: %xmode context
+    Exception reporting mode: Context
+
+    In [22]: %tb
+    ---------------------------------------------------------------------------
+    SystemExit                                Traceback (most recent call last)
+    <BLANKLINE>
+    ...<module>
+         29     except IndexError:
+         30         mode = 'div'
+    ---> 32     bar(mode)
+    <BLANKLINE>
+    ...bar(mode)
+         20         except:
+         21             stat = 1
+    ---> 22         sysexit(stat, mode)
+         23     else:
+         24         raise ValueError('Unknown mode')
+    <BLANKLINE>
+    ...sysexit(stat, mode)
+         10 def sysexit(stat, mode):
+    ---> 11     raise SystemExit(stat, f'Mode = {mode}')
+    <BLANKLINE>
+    SystemExit: (2, 'Mode = exit')
+
+    In [23]: %xmode verbose
+    Exception reporting mode: Verbose
+
+    In [24]: %tb
+    ---------------------------------------------------------------------------
+    SystemExit                                Traceback (most recent call last)
+    <BLANKLINE>
+    ... in <module>
+         29     except IndexError:
+         30         mode = 'div'
+    ---> 32     bar(mode)
+            mode = 'exit'
+    <BLANKLINE>
+    ... in bar(mode='exit')
+         20         except:
+         21             stat = 1
+    ---> 22         sysexit(stat, mode)
+            mode = 'exit'
+            stat = 2
+         23     else:
+         24         raise ValueError('Unknown mode')
+    <BLANKLINE>
+    ... in sysexit(stat=2, mode='exit')
+         10 def sysexit(stat, mode):
+    ---> 11     raise SystemExit(stat, f'Mode = {mode}')
+            stat = 2
+    <BLANKLINE>
+    SystemExit: (2, 'Mode = exit')
+    """
 
 
 def test_run_cell():