IPykernel Debugger

[mlucool]

Hi,

I tried 6.0.0a2 and found that while I could add breakpoints, variables did not appear.

The server has the following error:

Traceback (most recent call last):
  File "/path/to/myvenv/lib64/python3.7/site-packages/ipykernel/debugger.py", line 327, in stackTrace
    module_idx = len(sf_list) - next(i for i, v in enumerate(reversed(sf_list), 1) if v['name'] == '<module>' and i != 1)
StopIteration

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/path/to/myvenv/lib64/python3.7/site-packages/ipykernel/kernelbase.py", line 217, in process_control
    yield gen.maybe_future(handler(self.control_stream, idents, msg))
  File "/path/to/myvenv/lib64/python3.7/site-packages/tornado/gen.py", line 762, in run
    value = future.result()
  File "/path/to/myvenv/lib64/python3.7/site-packages/tornado/gen.py", line 769, in run
    yielded = self.gen.throw(*exc_info)  # type: ignore
  File "/path/to/myvenv/lib64/python3.7/site-packages/ipykernel/kernelbase.py", line 729, in debug_request
    reply_content = yield gen.maybe_future(self.do_debug_request(content))
  File "/path/to/myvenv/lib64/python3.7/site-packages/tornado/gen.py", line 762, in run
    value = future.result()
  File "/path/to/myvenv/lib64/python3.7/site-packages/tornado/gen.py", line 769, in run
    yielded = self.gen.throw(*exc_info)  # type: ignore
  File "/path/to/myvenv/lib64/python3.7/site-packages/ipykernel/ipkernel.py", line 410, in do_debug_request
    return (yield self.debugger.process_request(msg))
  File "/path/to/myvenv/lib64/python3.7/site-packages/tornado/gen.py", line 762, in run
    value = future.result()
  File "/path/to/myvenv/lib64/python3.7/site-packages/ipykernel/debugger.py", line 455, in process_request
    reply = await handler(message)
RuntimeError: coroutine raised StopIteration

[JohanMabille]

Hi,

It's weird that the line of the breakpoint is not highlighted on your screenshot. I failed to reproduce with last Jupyterlab, ipykernel 6.0.0a2 and python 3.7.10:

Can you list all the packages installed?

[mlucool]

Thanks for looking into this. I confirmed I also get this error on a different unrelated python setup.
Steps:

python -m venv myvenv 
source myvenv/bin/activate
pip install jupyterlab ipykernel==6.0.0a2
./myvenv/bin/jupyter-lab

Packages:

 % ./myvenv/bin/jupyter troubleshoot
You are using pip version 19.0.3, however version 21.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
$PATH:
	/path/to/myvenv/bin
	/usr/local/bin
	/usr/bin
	/bin
	/usr/sbin
	/sbin

sys.path:
	/path/to/myvenv/bin
	/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.7/lib/python37.zip
	/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.7/lib/python3.7
	/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.7/lib/python3.7/lib-dynload
	/path/to/myvenv/lib/python3.7/site-packages

sys.executable:
	/path/to/myvenv/bin/python3

sys.version:
	3.7.3 (default, Apr 24 2020, 18:51:23) 
	[Clang 11.0.3 (clang-1103.0.32.62)]

platform.platform():
	Darwin-20.3.0-x86_64-i386-64bit

which -a jupyter:
	/path/to/myvenv/bin/jupyter

pip list:
	Package             Version  
	------------------- ---------
	anyio               2.2.0    
	appnope             0.1.2    
	argon2-cffi         20.1.0   
	async-generator     1.10     
	attrs               20.3.0   
	Babel               2.9.0    
	backcall            0.2.0    
	bleach              3.3.0    
	certifi             2020.12.5
	cffi                1.14.5   
	chardet             4.0.0    
	debugpy             1.2.1    
	decorator           5.0.6    
	defusedxml          0.7.1    
	entrypoints         0.3      
	idna                2.10     
	importlib-metadata  3.10.0   
	ipykernel           6.0.0a2  
	ipython             7.22.0   
	ipython-genutils    0.2.0    
	jedi                0.18.0   
	Jinja2              2.11.3   
	json5               0.9.5    
	jsonschema          3.2.0    
	jupyter-client      6.1.13   
	jupyter-core        4.7.1    
	jupyter-packaging   0.7.12   
	jupyter-server      1.6.0    
	jupyterlab          3.0.13   
	jupyterlab-pygments 0.1.2    
	jupyterlab-server   2.4.0    
	MarkupSafe          1.1.1    
	mistune             0.8.4    
	nbclassic           0.2.7    
	nbclient            0.5.3    
	nbconvert           6.0.7    
	nbformat            5.1.3    
	nest-asyncio        1.5.1    
	notebook            6.3.0    
	packaging           20.9     
	pandocfilters       1.4.3    
	parso               0.8.2    
	pexpect             4.8.0    
	pickleshare         0.7.5    
	pip                 19.0.3   
	prometheus-client   0.10.1   
	prompt-toolkit      3.0.18   
	ptyprocess          0.7.0    
	pycparser           2.20     
	Pygments            2.8.1    
	pyparsing           2.4.7    
	pyrsistent          0.17.3   
	python-dateutil     2.8.1    
	pytz                2021.1   
	pyzmq               22.0.3   
	requests            2.25.1   
	Send2Trash          1.5.0    
	setuptools          40.8.0   
	six                 1.15.0   
	sniffio             1.2.0    
	terminado           0.9.4    
	testpath            0.4.4    
	tornado             6.1      
	traitlets           5.0.5    
	typing-extensions   3.7.4.3  
	urllib3             1.26.4   
	wcwidth             0.2.5    
	webencodings        0.5.1    
	zipp                3.4.1

[JohanMabille]

Everything looks correct regarding the packages.

Do you have the opportunity to install this test branch of ipykernel and run your code again? If so, you should see an array printed above the cell after executing it, can you copy - paste it here?

[mlucool]

Upgrading to that branch made the debugger work in the UI.

Upgrade:

pip install git+https://github.com/JohanMabille/ipykernel.git@debug_osx
...
Successfully built ipykernel
Installing collected packages: ipykernel
  Found existing installation: ipykernel 6.0.0a2
    Uninstalling ipykernel-6.0.0a2:
      Successfully uninstalled ipykernel-6.0.0a2
Successfully installed ipykernel-6.0.0.dev0

Output:

[{'id': 4, 'name': 'foo', 'line': 2, 'column': 1, 'source': {'path': '/var/folders/3b/n_bntsp9125gxpzmng1fm07m0000gn/T/ipykernel_15664/2016374787.py', 'sourceReference': 0}}, {'id': 5, 'name': '<module>', 'line': 5, 'column': 1, 'source': {'path': '/var/folders/3b/n_bntsp9125gxpzmng1fm07m0000gn/T/ipykernel_15664/2016374787.py', 'sourceReference': 0}}]

As a note, while you called the branch debug_osx, my original try was on linux.

[JohanMabille]

As a note, while you called the branch debug_osx, my original try was on linux.

I've ben misled by the platform log; interesting to know that this bug is not specific to MacOS.

The output you have (i.e. the stack frames before filtering) is actually what I have after filtering. In my cas, the stack trace goes back to process start, including all internal calls of ipykernel.

I will implement a "cargo-kulting" patch, but it would be nice to understand what is going on here. Out of curiosity, which python distribution do you use?

[mlucool]

$ python -V
Python 3.7.3
$ python -c 'import platform; print(platform.python_implementation())'
CPython