ipython 8+ python crash on exception

Since version 8 in Ipython I frequently - very frequently - get IPython crashes (termination) of the kind below.

I think the specific situation is that I edit code, I use autoreload(3), there is a bug, but when IPython tries traceback it crashes and terminates. Since a main point of using IPython is the auto-reload, this makes it almost unusable for development compared to Version 7.x.x. (Certainly distracting enough to spend the time to finally post it here.)

I have seen there is a few other bugs of that kind reported, but I was not sure which would be similar enough to any of them, hence I post this separately. My apologies for any duplications.

I am not sure whether the error is strictly reproducible as it happens in situations when code is edited.

I use Python 3.10.2 built from source on Linux (Fedora 34).

I am using pylab mode which loads matplotlib, I am not sure whether their event loop may interfere with IPython. Just a thought.

In [15]: m.plot1()
Error in sys.excepthook:
Traceback (most recent call last):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1979, in showtraceback
    stb = value._render_traceback_()
AttributeError: 'NotOneValueFound' object has no attribute '_render_traceback_'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1981, in showtraceback
    stb = self.InteractiveTB.structured_traceback(etype,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 1105, in structured_traceback
    return FormattedTB.structured_traceback(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 999, in structured_traceback
    return VerboseTB.structured_traceback(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 871, in structured_traceback
    formatted_exceptions += self.format_exception_as_a_whole(etype, evalue, etb, lines_of_context,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 804, in format_exception_as_a_whole
    frames.append(self.format_record(r))
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 723, in format_record
    result += ''.join(_format_traceback_lines(frame_info.lines, Colors, self.has_colors, lvals))
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 698, in lines
    pieces = self.included_pieces
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 649, in included_pieces
    pos = scope_pieces.index(self.executing_piece)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 628, in executing_piece
    return only(
  File "/home/alex/Python/lib/python3.10/site-packages/executing/executing.py", line 164, in only
    raise NotOneValueFound('Expected one value, found 0')
executing.executing.NotOneValueFound: Expected one value, found 0

Original exception was:
Traceback (most recent call last):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 3361, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-15-0de954ff7b19>", line 1, in <cell line: 1>
  File "/home/alex/python/source/multistar/base.py", line 586, in plot1
    rr = norm(self.y[self.y_rad])
AttributeError: 'Direct' object has no attribute 'y_rad'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1979, in showtraceback
    stb = value._render_traceback_()
AttributeError: 'AttributeError' object has no attribute '_render_traceback_'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 3301, in run_ast_nodes
    if await self.run_code(code, result, async_=asy):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 3378, in run_code
    self.showtraceback(running_compiled_code=True)
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1981, in showtraceback
    stb = self.InteractiveTB.structured_traceback(etype,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 1105, in structured_traceback
    return FormattedTB.structured_traceback(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 999, in structured_traceback
    return VerboseTB.structured_traceback(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 852, in structured_traceback
    formatted_exception = self.format_exception_as_a_whole(etype, evalue, etb, number_of_lines_of_context,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 804, in format_exception_as_a_whole
    frames.append(self.format_record(r))
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 723, in format_record
    result += ''.join(_format_traceback_lines(frame_info.lines, Colors, self.has_colors, lvals))
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 698, in lines
    pieces = self.included_pieces
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 649, in included_pieces
    pos = scope_pieces.index(self.executing_piece)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 628, in executing_piece
    return only(
  File "/home/alex/Python/lib/python3.10/site-packages/executing/executing.py", line 164, in only
    raise NotOneValueFound('Expected one value, found 0')
executing.executing.NotOneValueFound: Expected one value, found 0

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1979, in showtraceback
    stb = value._render_traceback_()
AttributeError: 'NotOneValueFound' object has no attribute '_render_traceback_'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 2900, in _run_cell
    return runner(coro)
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/async_helpers.py", line 129, in _pseudo_sync_runner
    coro.send(None)
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 3098, in run_cell_async
    has_raised = await self.run_ast_nodes(code_ast.body, cell_name,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 3320, in run_ast_nodes
    self.showtraceback()
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1981, in showtraceback
    stb = self.InteractiveTB.structured_traceback(etype,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 1105, in structured_traceback
    return FormattedTB.structured_traceback(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 999, in structured_traceback
    return VerboseTB.structured_traceback(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 871, in structured_traceback
    formatted_exceptions += self.format_exception_as_a_whole(etype, evalue, etb, lines_of_context,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 804, in format_exception_as_a_whole
    frames.append(self.format_record(r))
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 723, in format_record
    result += ''.join(_format_traceback_lines(frame_info.lines, Colors, self.has_colors, lvals))
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 698, in lines
    pieces = self.included_pieces
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 649, in included_pieces
    pos = scope_pieces.index(self.executing_piece)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 628, in executing_piece
    return only(
  File "/home/alex/Python/lib/python3.10/site-packages/executing/executing.py", line 164, in only
    raise NotOneValueFound('Expected one value, found 0')
executing.executing.NotOneValueFound: Expected one value, found 0

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1979, in showtraceback
    stb = value._render_traceback_()
AttributeError: 'NotOneValueFound' object has no attribute '_render_traceback_'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/alex/Python/bin/ipython3", line 8, in <module>
    sys.exit(start_ipython())
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/__init__.py", line 123, in start_ipython
    return launch_new_instance(argv=argv, **kwargs)
  File "/home/alex/Python/lib/python3.10/site-packages/traitlets/config/application.py", line 846, in launch_instance
    app.start()
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/terminal/ipapp.py", line 318, in start
    self.shell.mainloop()
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/terminal/interactiveshell.py", line 653, in mainloop
    self.interact()
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/terminal/interactiveshell.py", line 646, in interact
    self.run_cell(code, store_history=True)
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 2854, in run_cell
    result = self._run_cell(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 2905, in _run_cell
    self.showtraceback(running_compiled_code=True)
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1981, in showtraceback
    stb = self.InteractiveTB.structured_traceback(etype,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 1105, in structured_traceback
    return FormattedTB.structured_traceback(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 999, in structured_traceback
    return VerboseTB.structured_traceback(
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 871, in structured_traceback
    formatted_exceptions += self.format_exception_as_a_whole(etype, evalue, etb, lines_of_context,
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 804, in format_exception_as_a_whole
    frames.append(self.format_record(r))
  File "/home/alex/Python/lib/python3.10/site-packages/IPython/core/ultratb.py", line 723, in format_record
    result += ''.join(_format_traceback_lines(frame_info.lines, Colors, self.has_colors, lvals))
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 698, in lines
    pieces = self.included_pieces
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 649, in included_pieces
    pos = scope_pieces.index(self.executing_piece)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/home/alex/Python/lib/python3.10/site-packages/stack_data/core.py", line 628, in executing_piece
    return only(
  File "/home/alex/Python/lib/python3.10/site-packages/executing/executing.py", line 164, in only
    raise NotOneValueFound('Expected one value, found 0')
executing.executing.NotOneValueFound: Expected one value, found 0

[alexmojaki]

New fix is released in executing 1.0.0!

[jaseg]

Here’s a repro for this. On my system I was able to consistently trigger this type of exception by importlib.reload’ing a module. It seems ipython gets confused when the module changes on disk and the old source location of the error does not align with the new source location. I can imagine that running conda/pip/other package managers while ipython is running may also cause this issue.

I’m running jupyterlab 3.4.3, jupyter-nbclassic 0.3.7, jupyter-notebook 6.4.12, and python 3.10.5 on Arch Linux x86_64.

To reproduce, run these three ipython cells in order:

Cell 1

import importlib
import sys
from pathlib import Path

tmpdir = Path('/tmp/traceback_exc_test')
tmpdir.mkdir(exist_ok=True)
sys.path.append(str(tmpdir))

(tmpdir / 'ipy_err_test_module.py').write_text('print("imported version 1")\ndef crash_and_burn():\n    raise ValueError()')

import ipy_err_test_module
try:
    ipy_err_test_module.crash_and_burn()
except:
    pass

Output:

imported version 1

Cell 2

(tmpdir / 'ipy_err_test_module.py').write_text('print("imported version 2")\n\n\ndef crash_and_burn():\n    raise SystemError()')

importlib.reload(ipy_err_test_module)
ipy_err_test_module.crash_and_burn()

Output:

---------------------------------------------------------------------------
SystemError                               Traceback (most recent call last)
Input In [2], in <cell line: 4>()
      1 (tmpdir / 'ipy_err_test_module.py').write_text('print("imported version 2")\n\n\ndef crash_and_burn():\n    raise SystemError()')
      3 importlib.reload(ipy_err_test_module)
----> 4 ipy_err_test_module.crash_and_burn()

File /tmp/traceback_exc_test/ipy_err_test_module.py:5, in crash_and_burn()
      4 def crash_and_burn():
----> 5     raise SystemError()

SystemError: 

Cell 3

(tmpdir / 'ipy_err_test_module.py').write_text('print("imported version 2")\n\n\n\n\n\n\ndef crash_and_burn():\n    raise SystemError()')

importlib.reload(ipy_err_test_module)
ipy_err_test_module.crash_and_burn()

Output:

(tmpdir / 'ipy_err_test_module.py').write_text('print("imported version 2")\n\n\n\n\n\n\ndef crash_and_burn():\n    raise SystemError()')

​

importlib.reload(ipy_err_test_module)

ipy_err_test_module.crash_and_burn()

imported version 2
Unexpected exception formatting exception. Falling back to standard exception

Traceback (most recent call last):
  File "/usr/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 3398, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "/tmp/ipykernel_5390/429422080.py", line 4, in <cell line: 4>
    ipy_err_test_module.crash_and_burn()
  File "/tmp/traceback_exc_test/ipy_err_test_module.py", line 9, in crash_and_burn
    raise SystemError()
SystemError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 1993, in showtraceback
    stb = self.InteractiveTB.structured_traceback(
  File "/usr/lib/python3.10/site-packages/IPython/core/ultratb.py", line 1118, in structured_traceback
    return FormattedTB.structured_traceback(
  File "/usr/lib/python3.10/site-packages/IPython/core/ultratb.py", line 1012, in structured_traceback
    return VerboseTB.structured_traceback(
  File "/usr/lib/python3.10/site-packages/IPython/core/ultratb.py", line 865, in structured_traceback
    formatted_exception = self.format_exception_as_a_whole(etype, evalue, etb, number_of_lines_of_context,
  File "/usr/lib/python3.10/site-packages/IPython/core/ultratb.py", line 818, in format_exception_as_a_whole
    frames.append(self.format_record(r))
  File "/usr/lib/python3.10/site-packages/IPython/core/ultratb.py", line 736, in format_record
    result += ''.join(_format_traceback_lines(frame_info.lines, Colors, self.has_colors, lvals))
  File "/usr/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/usr/lib/python3.10/site-packages/stack_data/core.py", line 698, in lines
    pieces = self.included_pieces
  File "/usr/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/usr/lib/python3.10/site-packages/stack_data/core.py", line 649, in included_pieces
    pos = scope_pieces.index(self.executing_piece)
  File "/usr/lib/python3.10/site-packages/stack_data/utils.py", line 145, in cached_property_wrapper
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/usr/lib/python3.10/site-packages/stack_data/core.py", line 628, in executing_piece
    return only(
  File "/usr/lib/python3.10/site-packages/executing/executing.py", line 164, in only
    raise NotOneValueFound('Expected one value, found 0')
executing.executing.NotOneValueFound: Expected one value, found 0