Fix Ctrl-C segfaults in sage.libs.gap

src/sage/doctest/util.py

@@ -883,9 +883,16 @@ def ensure_interruptible_after(seconds: float, max_wait_after_interrupt: float =
 
     try:
         yield data
-    except AlarmInterrupt as e:
-        e.__traceback__ = None  # workaround for https://github.com/python/cpython/pull/129276
-        alarm_raised = True
+    except KeyboardInterrupt as e:
+        # AlarmInterrupt is a subclass of KeyboardInterrupt, so this
+        # catches both. The "user interrupt" message is a quirk of
+        # GAP interrupts that result from SIGALRM.
+        if isinstance(e, AlarmInterrupt) or "user interrupt" in str(e):
+            # workaround for https://github.com/python/cpython/pull/129276
+            e.__traceback__ = None
+            alarm_raised = True
+        else:
+            raise
     finally:
         before_cancel_alarm_elapsed = walltime() - start_time
         cancel_alarm()