Issue #16491: IDLE now prints chained exception tracebacks.
diff --git a/Lib/idlelib/run.py b/Lib/idlelib/run.py
index 5365680..b0a4794 100644
--- a/Lib/idlelib/run.py
+++ b/Lib/idlelib/run.py
@@ -158,15 +158,32 @@
efile = sys.stderr
typ, val, tb = excinfo = sys.exc_info()
sys.last_type, sys.last_value, sys.last_traceback = excinfo
- tbe = traceback.extract_tb(tb)
- print('Traceback (most recent call last):', file=efile)
- exclude = ("run.py", "rpc.py", "threading.py", "queue.py",
- "RemoteDebugger.py", "bdb.py")
- cleanup_traceback(tbe, exclude)
- traceback.print_list(tbe, file=efile)
- lines = traceback.format_exception_only(typ, val)
- for line in lines:
- print(line, end='', file=efile)
+ seen = set()
+
+ def print_exc(typ, exc, tb):
+ seen.add(exc)
+ context = exc.__context__
+ cause = exc.__cause__
+ if cause is not None and cause not in seen:
+ print_exc(type(cause), cause, cause.__traceback__)
+ print("\nThe above exception was the direct cause "
+ "of the following exception:\n", file=efile)
+ elif context is not None and context not in seen:
+ print_exc(type(context), context, context.__traceback__)
+ print("\nDuring handling of the above exception, "
+ "another exception occurred:\n", file=efile)
+ if tb:
+ tbe = traceback.extract_tb(tb)
+ print('Traceback (most recent call last):', file=efile)
+ exclude = ("run.py", "rpc.py", "threading.py", "queue.py",
+ "RemoteDebugger.py", "bdb.py")
+ cleanup_traceback(tbe, exclude)
+ traceback.print_list(tbe, file=efile)
+ lines = traceback.format_exception_only(typ, exc)
+ for line in lines:
+ print(line, end='', file=efile)
+
+ print_exc(typ, val, tb)
def cleanup_traceback(tb, exclude):
"Remove excluded traces from beginning/end of tb; get cached lines"