regression: 0.28.3 fails to respond to `initialize` request, stalls and consumes high CPU

I’m working on an LSP client, and hoping to support jedi-language-server. When I started implementing, 0.27.2 was current, and this worked well. However, in testing, one of my testers reported that the client was hanging waiting for jedi-language-server.

Upon investigation, I found that the relevant difference was that the tester was running 0.28.3 rather than my 0.27.2, and upon updating my own installation of jedi-language-server to 0.28.3 I was able to reproduce the same symptom.

Platform: macOS 10.15.7 Python: 3.9.2 jedi-language-server: 0.28.3 Client: n/a

I don’t have a clean test harness for reproducing this; I thought I could start jedi-language-server in a Terminal window and pipe or paste JSON into it, but that doesn’t seem to work as expected. However, I have provided the JSON that is being sent to the server when it starts up, perhaps that is useful.

The regression is reproducible: use pip install -U jedi-language-server to install the current version (0.28.3 as I write this), and the server never responds to the initialize message. Sometimes it appears to continue running and consume high CPU, I have attached a macOS sample report, in case that is helpful.

Then, use pip uninstall jedi-language-server followed by pip install -Iv jedi-language-server==0.27.2 to install the older version, and the language server responds immediately and as expected to initialize and other protocol requests.

Thanks for reading; please let me know if there’s any additional information I can provide.

initialize.json.zip jedi-ls-sample.txt

[siegel]

Got it! It didn’t go exactly as planned, but I was able to crowbar in a full path to the development build, and confirmed that the server responds as expected to initialization and other requests that I tested.

Thanks very much! I really appreciate the quick fix.

While I’m at it, I just wanted to throw some love your way for generating fully qualified snippet information for function completions. It makes this client developer’s life much happier, and my customers will appreciate it as well. ❤️

[siegel]

So, I did pip uninstall jedi-language-server followed by pip install -U jedi-language-server, and did indeed note the new version 0.28.4. However, when starting the server, I get the following (reproducible from the command line):

siegel ~ % jedi-language-server
Traceback (most recent call last):
  File "/usr/local/bin/jedi-language-server", line 5, in <module>
    from jedi_language_server.cli import cli
  File "/usr/local/lib/python3.9/site-packages/jedi_language_server/cli.py", line 5, in <module>
    from .server import SERVER
  File "/usr/local/lib/python3.9/site-packages/jedi_language_server/server.py", line 15, in <module>
    from pygls.lsp.methods import (
  File "/usr/local/lib/python3.9/site-packages/pygls/lsp/__init__.py", line 19, in <module>
    from pygls.exceptions import MethodTypeNotRegisteredError
ImportError: cannot import name 'MethodTypeNotRegisteredError' from 'pygls.exceptions' (/usr/local/lib/python3.9/site-packages/pygls/exceptions.py)

Unclear to me where the issue lies, and it may not be your issue to solve.