jupyterlab-desktop: Jupyter Server Not Found (executable not in PATH)

Description

When starting jupyterlab_app, I get the message:

Jupyter Server Not Found We were unable to launch a Jupyter server, which is a prerequisite for JupyterLab Native. If Jupyter is installed as a python module, but the python executable is not in your PATH, specify the executable location below. Otherwise, try installing or updating Jupyter. The Jupyter notebook version must be 4.3.0 or greater.

Despite a) having a working jupyter-lab installation that I can spin up from the terminal and which appears in the browser, b) having the python executable in my path, and c) having the requisite version of jupyter.

When I manually point jupyterlab_app to the python executable (/Users/aschuler/.pyenv/shims/python) via the CHOOSE PATH it spins the icon again for a moment and then returns the same “Server Not Found” message.

Context

I am running python through pyenv, which may be the issue here. Relevant information:

aschuler@Alejandros-MacBook-Air ~ % pyenv versions
  system
* 3.9.6 (set by /Users/aschuler/.pyenv/version)

aschuler@Alejandros-MacBook-Air ~ % echo $PATH    
/Users/aschuler/.pyenv/shims:/Applications/Sublime Text.app/Contents/SharedSupport/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin

aschuler@Alejandros-MacBook-Air ~ % jupyter --version
jupyter core     : 4.7.1
jupyter-notebook : 6.4.0
qtconsole        : 5.1.1
ipython          : 7.26.0
ipykernel        : 6.0.3
jupyter client   : 6.1.12
jupyter lab      : 3.1.13
nbconvert        : 6.1.0
ipywidgets       : 7.6.3
nbformat         : 5.1.3
traitlets        : 5.0.5

aschuler@Alejandros-MacBook-Air ~ % which python
/Users/aschuler/.pyenv/shims/python

aschuler@Alejandros-MacBook-Air ~ % which jupyter-lab
/Users/aschuler/.pyenv/shims/jupyter-lab

(MK): Extra details from title: jupyterlab_app fails to start on MacOS 11.5.2 with (pyenv issue?)

About this issue

Original URL
State: closed
Created 3 years ago
Comments: 50 (19 by maintainers)

Most upvoted comments

@krassowski I’d love to try that, but, as I said, I can’t get the app to even start the server. Based on my understanding, I can’t really do anything about the kernel without a running server in the first place, right?

alejandroschuler on Sep 25, 2021

Hi @Kaisershmarren, @flashypepo, @alejandroschuler, @pybokeh the newly released v3.2.4-2 contains two fixes for this problem - would you mind testing it and letting us know if it works for you well now?

If it does not could you please provide the logs from:

on Linux: ~/.config/jupyterlab-desktop/logs/main.log
on macOS: ~/Library/Logs/jupyterlab-desktop/main.log
on Windows: %USERPROFILE%\AppData\Roaming\jupyterlab-desktop\logs\main.log

krassowski on Nov 27, 2021

Same thing happens with me, except I’m on Windows 10 OS. For some reason, it keeps thinking it should search for the python.exe located in the C:\JupyterLab folder despite me manually pointing it to the python.exe of the Python virtual env that has jupyterlab and server installed.

EDIT: I am using just venv module for my virtual environments, not pyenv.

pybokeh on Sep 23, 2021

Great work, @krassowski!!! It perfectly works, now. Immagine 27-11-21 alle 15 18

Thank you so much.

Kaisershmarren on Nov 27, 2021

Dear @krassowski, first of all thank you so much for your update. Now I can send you all info:

After changing Conda environment, the app gave me this error:
After the command jlab --verbose 4, the same form opened and saved these files: renderer.log main.log

Feel free to ask me other tests…

Kaisershmarren on Nov 23, 2021

Ok. Perfect. Here’s the output.

(mobile_net_ssd2) max@MacBook-Pro-di-Massimiliano jupyterlab-desktop % /Users/max/opt/anaconda3/envs/mobile_net_ssd2/bin/python -m jupyterlab --no-browser --JupyterApp.config_file_name=‘’

[I 2021-11-18 20:18:27.422 ServerApp] jupyterlab | extension was successfully linked. [I 2021-11-18 20:18:27.707 ServerApp] nbclassic | extension was successfully linked. [I 2021-11-18 20:18:27.779 LabApp] JupyterLab extension loaded from /Users/max/opt/anaconda3/envs/mobile_net_ssd2/lib/python3.6/site-packages/jupyterlab [I 2021-11-18 20:18:27.779 LabApp] JupyterLab application directory is /Users/max/opt/anaconda3/envs/mobile_net_ssd2/share/jupyter/lab [I 2021-11-18 20:18:27.783 ServerApp] jupyterlab | extension was successfully loaded. [I 2021-11-18 20:18:27.788 ServerApp] nbclassic | extension was successfully loaded. [I 2021-11-18 20:18:27.788 ServerApp] Serving notebooks from local directory: /Users/max/Library/Application Support/jupyterlab-desktop [I 2021-11-18 20:18:27.788 ServerApp] Jupyter Server 1.4.1 is running at: [I 2021-11-18 20:18:27.788 ServerApp] http://localhost:8888/lab?token=xxxxxx [I 2021-11-18 20:18:27.788 ServerApp] or http://127.0.0.1:8888/lab?token=xxxxxxx [I 2021-11-18 20:18:27.789 ServerApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation). [C 2021-11-18 20:18:27.794 ServerApp]

To access the server, open this file in a browser:
    file:///Users/max/Library/Jupyter/runtime/jpserver-2280-open.html
Or copy and paste one of these URLs:
    http://localhost:8888/lab?token=xxxxxx
 or http://127.0.0.1:8888/lab?token=xxxxxx

Kaisershmarren on Nov 18, 2021

Dear @krassowski, the version of JupyterLab is the 3.2.1:

Name: jupyterlab Version: 3.2.1 Summary: JupyterLab computational environment Home-page: https://jupyter.org Author: Jupyter Development Team Author-email: jupyter@googlegroups.com License: UNKNOWN Location: /Users/max/opt/anaconda3/envs/mobile_net_ssd2/lib/python3.6/site-packages Requires: jinja2, packaging, ipython, jupyterlab-server, tornado, jupyter-core, jupyter-server, nbclassic Required-by:

When you’re saying to start JupiterLab are you meaning to start jupyter-server ? If so, this is the console output:

[I 2021-11-18 19:15:04.997 ServerApp] jupyterlab | extension was successfully linked. [I 2021-11-18 19:15:05.506 ServerApp] nbclassic | extension was successfully linked. [I 2021-11-18 19:15:05.600 LabApp] JupyterLab extension loaded from /Users/max/opt/anaconda3/envs/mobile_net_ssd2/lib/python3.6/site-packages/jupyterlab [I 2021-11-18 19:15:05.600 LabApp] JupyterLab application directory is /Users/max/opt/anaconda3/envs/mobile_net_ssd2/share/jupyter/lab [I 2021-11-18 19:15:05.605 ServerApp] jupyterlab | extension was successfully loaded. [I 2021-11-18 19:15:05.613 ServerApp] nbclassic | extension was successfully loaded. [I 2021-11-18 19:15:05.613 ServerApp] Serving notebooks from local directory: /Users/max/Library/Application Support/jupyterlab-desktop [I 2021-11-18 19:15:05.613 ServerApp] Jupyter Server 1.4.1 is running at: [I 2021-11-18 19:15:05.613 ServerApp] http://localhost:8888/?token=xxxxxxx [I 2021-11-18 19:15:05.613 ServerApp] or http://127.0.0.1:8888/?token=xxxxxxx [I 2021-11-18 19:15:05.613 ServerApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation). [C 2021-11-18 19:15:05.619 ServerApp]

To access the server, open this file in a browser:
    file:///Users/max/Library/Jupyter/runtime/jpserver-792-open.html
Or copy and paste one of these URLs:
    http://localhost:8888/?token=xxxxxxx
 or http://127.0.0.1:8888/?token=xxxxxxx

I don’t know if it could be useful, but I also managed to start JupiterNotebook (of course it’s not nice to use as the desktop version… but it’s working…) from Anaconda Navigator (in the section of environments): Search Environments

Kaisershmarren on Nov 18, 2021