Jupyter lab 4.0.6 error on startup about yarn configuration and worker_threads

JupyterLab
1

I’m getting the following error when starting jupyter lab:

% Fail to get yarn configuration. internal/modules/cjs/loader.js:582
    throw err;
    ^

Error: Cannot find module 'worker_threads'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:580:15)
    at Function.Module._load (internal/modules/cjs/loader.js:506:25)
    at Module.require (internal/modules/cjs/loader.js:636:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at /misc/working/projects/pysicr/test_deployment/lib/python3.9/site-packages/jupyterlab/staging/yarn.js:423:2576
    at Object.<anonymous> (/misc/working/projects/pysicr/test_deployment/lib/python3.9/site-packages/jupyterlab/staging/yarn.js:743:8770)
    at Module._compile (internal/modules/cjs/loader.js:688:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:699:10)
    at Module.load (internal/modules/cjs/loader.js:598:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:537:12)

This is not fatal. Things seem to be working fine anyway, but I have not tested a lot of stuff.

Jupyter is installed in a vitualenv with python 3.9 in centos 7.

The only changes I had to make during the installation was to downgrade urllib3 to <2.0, because the default installed as a requirement was giving other errors.

Thanks,
JP

2

Thanks for the report. What version of nodejs is this against?

If this is a “long term” build that will be frequently restarted, one can also configure the startup to avoid all nodejs-based things, which generally are neither useful or interesting for 4.x (which generally prefers pre-built extensions):

https://jupyterlab.readthedocs.io/en/stable/user/directories.html#disabling-rebuild-checks

e.g. in jupyter_server_config.json:

{
  "LabApp": {
    "tornado_settings": {
      "page_config_data": {
        "buildCheck": false,
        "buildAvailable": false,
      }
    }
  }
}

This can help both startup time and stability.

3

Are you saying these errors are not related to the operation of Jupyter server or lab, and it’s something about the build check on startup?

My use case is that I have several users and I try to maintain a common stable environment for them. But people are starting/restarting Jupyter all the time. If this error is harmless, then I’d be happy to find a way to suppress it / prevent it.

I will try your suggestions.

4

Similar issue as jpcarm

Fail to get yarn configuration. internal/modules/cjs/loader.js:638
    throw err;
    ^

Error: Cannot find module 'worker_threads'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:636:15)
    at Function.Module._load (internal/modules/cjs/loader.js:562:25)
    at Module.require (internal/modules/cjs/loader.js:692:17)
    at require (internal/modules/cjs/helpers.js:25:18)
    at /home/luca/mambaforge/lib/python3.10/site-packages/jupyterlab/staging/yarn.js:423:2576
    at Object.<anonymous> (/home/luca/mambaforge/lib/python3.10/site-packages/jupyterlab/staging/yarn.js:743:8770)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)

This message is no longer showing after updating node.js .
The easiest way to update on my system (linux mint) was to use NVM.
install node.js on Linux Mint

using

Step 2: Install Node.js via NVM

Hope it helps