Python language server crashes with large files open

[pankajp]

Environment data

• VS Code version: 1.28.2 (User Setup)
• Extension version (available under the Extensions sidebar): 2018.9.1
• OS and version: Windows 10
• Python version (& distribution if applicable, e.g. Anaconda): Anaconda, python 3.7.0
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): conda root env
• Relevant/affected Python packages and their versions: -

Actual behavior

Python language server continually crashes (I have some pretty large python files open) and a window frequently pops up with following message.

Carried forward from: #2108

Expected behavior

Thing should run normally, if a file cannot be handled it should inform me as such and at least not crash.

Steps to reproduce:

1. Open VSCode with files

Logs

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

Starting Microsoft Python language server.
Downloading https://pvsc.blob.core.windows.net/python-language-server-stable/Python-Language-Server-win-x64.0.1.48.nupkg... complete.
Unpacking archive... done.
Microsoft Python Language Server version 0.1.48.0
Initializing for C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\python.exe
Reloading modules... 
done.
Reloading modules... 

Process is terminating due to StackOverflowException.
[Info  - 10:15:09 PM] Connection to server got closed. Server will restart.
Microsoft Python Language Server version 0.1.48.0
Initializing for C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\python.exe

Process is terminating due to StackOverflowException.
[Info  - 10:17:00 PM] Connection to server got closed. Server will restart.
Microsoft Python Language Server version 0.1.48.0
Initializing for C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\python.exe

Process is terminating due to StackOverflowException.
[Info  - 10:18:18 PM] Connection to server got closed. Server will restart.
Microsoft Python Language Server version 0.1.48.0
Initializing for C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\python.exe
##########Linting Output - pylint##########
************* Module opt_recipes
5128,0,warning,W0301:Unnecessary semicolon
5177,0,warning,W0301:Unnecessary semicolon
17519,0,warning,W0301:Unnecessary semicolon

...


10618,8,warning,W0612:Unused variable 'index'
10626,16,warning,W0612:Unused variable 'lindex'
10922,8,warning,W0612:Unused variable 'm'

Process is terminating due to StackOverflowException.
[Info  - 10:19:18 PM] Connection to server got closed. Server will restart.
Microsoft Python Language Server version 0.1.48.0
Initializing for C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\python.exe

Process is terminating due to StackOverflowException.
[Info  - 10:20:23 PM] Connection to server got closed. Server will restart.
Microsoft Python Language Server version 0.1.48.0
Initializing for C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\python.exe

Process is terminating due to StackOverflowException.
[Info  - 10:21:27 PM] Connection to server got closed. Server will restart.
Microsoft Python Language Server version 0.1.48.0
Initializing for C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\python.exe

[...repeats indefinitely...]

Output from Console under the Developer Tools panel (toggle Developer Tools on under Help)

/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:4274 Overwriting grammar scope name to file mapping for scope text.html.django.
Old grammar file: file:///c%3A/Users/ppandey/.vscode/extensions/batisteo.vscode-django-0.17.0/syntaxes/django-html.tmLanguage.json.
New grammar file: file:///c%3A/Users/ppandey/.vscode/extensions/bibhasdn.django-html-1.2.0/syntaxes/django-html.json
e.register @ /C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:4274
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:4274 Overwriting grammar scope name to file mapping for scope source.python.
Old grammar file: file:///c%3A/Users/ppandey/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/extensions/python/syntaxes/MagicPython.tmLanguage.json.
New grammar file: file:///c%3A/Users/ppandey/.vscode/extensions/magicstack.magicpython-1.1.0/grammars/MagicPython.tmLanguage
e.register @ /C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:4274
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:1409  INFO no standard startup: not just one window
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] activating extension
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] starting language server
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:1409   ERR File(s) not opened on this client.

/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] rejected promise not handled within 1 second
t.log @ /C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] Traceback (most recent call last):
  File "C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\Scripts\jupyter-notebook-script.py", line 6, in <module>
    from notebook.notebookapp import main
  File "C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\lib\site-packages\notebook\notebookapp.py", line 46, in <module>
    from zmq.eventloop import ioloop
  File "C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\lib\site-packages\zmq\__init__.py", line 47, in <module>
    from zmq import backend
  File "C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\lib\site-packages\zmq\backend\__init__.py", line 40, in <module>
    reraise(*exc_info)
  File "C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\lib\site-packages\zmq\utils\sixcerpt.py", line 34, in reraise
    raise value
  File "C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\lib\site-packages\zmq\backend\__init__.py", line 27, in <module>
    _ns = select_backend(first)
  File "C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\lib\site-packages\zmq\backend\select.py", line 27, in select_backend
    mod = __import__(name, fromlist=public_api)
  File "C:\Users\ppandey\AppData\Local\Continuum\Anaconda3\lib\site-packages\zmq\backend\cython\__init__.py", line 6, in <module>
    from . import (constants, error, message, context,
ImportError: DLL load failed: The specified module could not be found.

t.log @ /C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] Python Extension: Listing Nuget Packages, Arg 1: "https://pvsc.blob.core.windows.net", Arg 2: "python-language-server-stable", Arg 3: "Python-Language-Server-win-x64"
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] Python Extension: Get latest language server nuget package version, , Return Value: {"package":"Python-Language-Server-win-x64.0.1.48.nupkg","uri":"https://pvsc.blob.core.windows.net/python-language-server-stable/Python-Language-Server-win-x64.0.1.48.nupkg","version":{"loose":true,"raw":"0.1.48","major":0,"minor":1,"patch":48,"prerelease":[],"build":[],"version":"0.1.48"}}
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] Python Extension: Get latest version of Language Server, , Return Value: {"package":"Python-Language-Server-win-x64.0.1.48.nupkg","uri":"https://pvsc.blob.core.windows.net/python-language-server-stable/Python-Language-Server-win-x64.0.1.48.nupkg","version":{"loose":true,"raw":"0.1.48","major":0,"minor":1,"patch":48,"prerelease":[],"build":[],"version":"0.1.48"}}
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] Python Extension: Get language server folder name, , Return Value: "languageServer.0.1.48"
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] Python Extension: Listing Nuget Packages, Arg 1: "https://pvsc.blob.core.windows.net", Arg 2: "python-language-server-stable", Arg 3: "Python-Language-Server-win-x64"
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] Python Extension: Get latest language server nuget package version, , Return Value: {"package":"Python-Language-Server-win-x64.0.1.48.nupkg","uri":"https://pvsc.blob.core.windows.net/python-language-server-stable/Python-Language-Server-win-x64.0.1.48.nupkg","version":{"loose":true,"raw":"0.1.48","major":0,"minor":1,"patch":48,"prerelease":[],"build":[],"version":"0.1.48"}}
/C:/Users/ppandey/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.main.js:282 [Extension Host] Python Extension: Get latest version of Language Server, , Return Value: {"package":"Python-Language-Server-win-x64.0.1.48.nupkg","uri":"https://pvsc.blob.core.windows.net/python-language-server-stable/Python-Language-Server-win-x64.0.1.48.nupkg","version":{"loose":true,"raw":"0.1.48","major":0,"minor":1,"patch":48,"prerelease":[],"build":[],"version":"0.1.48"}}

[brettcannon]

Can you help give us a concept of what "large" and "some" is? Are we talking 10,000 lines of code? A million? And do you have 3 such files open? 20? Any chance you can share the files with us?

FYI I've opened a relevant issue with the language server if you want to answer the questions over there.

[MikhailArkhipov]

@pankajp - did it happen before or it is new in the .48?

[pankajp]

This is not a new issue. Moving further discussion to the upstream gh issue created by Brett ( microsoft/python-language-server#309 ). Thanks

[luabud]

Fixed upstream (microsoft/python-language-server#309)