jupyterlab_code_formatter Jupyterlab Code Formatter Error Unable to find server plugin version

Checklist prior to opening an issue

[X] I have followed fully the installation steps laid out in the documentation site.
[X] I have restarted jupyterlab.
[X] I have read the FAQ section in the documentation site.

Describe the bug After JupyterLab server start, opening a client yields the following popup:

Jupyterlab Code Formatter Error
Unable to find server plugin version, this should be impossible, open a GitHub issue if you cannot figure this issue out yourself.

Diagnostic commands Please attach the output of the following commands (please format them properly)

pip freeze

anyio==2.0.2
appdirs==1.4.4
argon2-cffi==20.1.0
arviz==0.10.0
astroid==2.4.2
async-generator==1.10
atomicwrites==1.1.5
attrs==20.3.0
Automat==20.2.0
autopep8==1.5.4
Babel==2.9.0
backcall==0.2.0
beautifulsoup4==4.9.3
black==20.8b1
bleach==3.2.1
blinker==1.4
boto==2.49.0
certifi==2020.12.5
cffi==1.14.4
cftime==1.3.0
chardet==4.0.0
click==7.1.2
cloud-init==20.4
colorama==0.4.4
command-not-found==0.3
configobj==5.0.6
constantly==15.1.0
cryptography==3.3.1
cssselect==1.1.0
cupshelpers==1.0
cvxopt==1.2.3
cycler==0.10.0
dbus-python==1.2.16
decorator==4.4.2
defer==1.0.6
defusedxml==0.6.0
dill==0.3.3
distro==1.5.0
distro-info===0.23ubuntu1
entrypoints==0.3
et-xmlfile==1.0.1
fastprogress==1.0.0
filelock==3.0.12
flake8==3.8.4
h5py==3.1.0
html5lib==1.1
httplib2==0.18.1
hyperlink==21.0.0
idna==2.10
importlib-metadata==3.4.0
incremental==17.5.0
ipykernel==5.4.3
ipympl==0.6.2
ipython==7.19.0
ipython-genutils==0.2.0
ipywidgets==7.6.3
isort==5.7.0
itemadapter==0.2.0
itemloaders==1.0.4
jdcal==1.0
jedi==0.17.2
jeepney==0.6.0
Jinja2==2.11.2
jmespath==0.10.0
joblib==0.14.0
json5==0.9.5
jsonpatch==1.28
jsonpointer==2.0
jsonschema==3.2.0
jupyter==1.0.0
jupyter-client==6.1.11
jupyter-console==6.2.0
jupyter-core==4.7.0
jupyter-resource-usage==0.5.1
jupyter-server==1.2.1
jupyterlab==3.0.4
jupyterlab-code-formatter==1.4.1
jupyterlab-pygments==0.1.2
jupyterlab-server==2.1.2
jupyterlab-widgets==1.0.0
keyring==21.8.0
kiwisolver==1.3.1
language-selector==0.1
launchpadlib==1.10.13
lazr.restfulclient==0.14.3
lazr.uri==1.0.5
lazy-object-proxy==1.4.3
llvmlite==0.31.0
lxml==4.6.2
macaroonbakery==1.3.1
MarkupSafe==1.1.1
matplotlib==3.3.3
mccabe==0.6.1
mistune==0.8.4
modbus-cli==0.1.3
more-itertools==8.6.0
mypy-extensions==0.4.3
mysqlclient==1.4.4
nbclassic==0.2.6
nbclient==0.5.1
nbconvert==6.0.7
nbformat==5.0.8
nest-asyncio==1.4.3
netCDF4==1.5.5.1
netifaces==0.10.9
nose==1.3.7
notebook==6.1.6
numba==0.48.0
numexpr==2.7.1
numpy==1.19.4
oauthlib==3.1.0
olefile==0.46
openpyxl==3.0.3
packaging==20.8
pandas==1.2.0
pandocfilters==1.4.3
parsel==1.6.0
parso==0.7.1
pathspec==0.8.1
patsy==0.5.1
pbr==5.5.1
pexpect==4.8.0
pickleshare==0.7.5
Pillow==8.1.0
pip-tools==5.5.0
pluggy==0.13.1
prometheus-client==0.9.0
prompt-toolkit==3.0.10
Protego==0.1.16
protobuf==3.14.0
psutil==5.8.0
ptyprocess==0.7.0
py==1.8.1
pyasn1==0.4.8
pyasn1-modules==0.2.8
pycairo==1.16.2
pycodestyle==2.6.0
pycparser==2.20
pycups==1.9.73
PyDispatcher==2.0.5
pydocstyle==5.1.1
pyflakes==2.2.0
pyftdi==0.52.9
Pygments==2.7.4
PyGObject==3.36.0
PyHamcrest==2.0.2
PyJWT==1.7.1
pylint==2.6.0
pymacaroons==0.13.0
pymc3==3.10.0
PyNaCl==1.4.0
pyOpenSSL==20.0.1
pyparsing==2.4.7
pyRFC3339==1.1
pyrsistent==0.17.3
pyserial==3.5
pytest==4.6.9
python-apt==2.0.0+ubuntu0.20.4.3
python-dateutil==2.8.1
python-debian==0.1.39
python-jsonrpc-server==0.4.0
python-language-server==0.36.2
pytz==2020.5
pyusb==1.1.0
PyYAML==5.3.1
pyzmq==20.0.0
qtconsole==5.0.1
QtPy==1.9.0
queuelib==1.5.0
regex==2020.11.13
requests==2.25.1
requests-unixsocket==0.2.0
rope==0.18.0
scikit-learn==0.22.2.post1
scipy==1.5.4
Scrapy==2.4.1
seaborn==0.11.1
SecretStorage==3.3.0
Send2Trash==1.5.0
service-identity==18.1.0
sidetable==0.8.0
simplejson==3.17.2
six==1.15.0
sklearn-pandas==1.8.0
sniffio==1.2.0
snowballstemmer==2.0.0
sos==4.0
soupsieve==2.1
ssh-import-id==5.11
statsmodels==0.11.1
systemd-python==234
tables==3.6.1
terminado==0.9.2
testpath==0.4.4
testresources==2.0.1
Theano==1.0.5
Theano-PyMC==1.1.0
toml==0.10.2
tornado==6.1
traitlets==5.0.5
Twisted==20.3.0
typed-ast==1.4.2
typing-extensions==3.7.4.3
ubuntu-advantage-tools==20.3
ufw==0.36
ujson==4.0.1
uModbus==1.0.4
unattended-upgrades==0.1
urllib3==1.26.2
w3lib==1.22.0
wadllib==1.3.4
wcwidth==0.2.5
webencodings==0.5.1
widgetsnbextension==3.5.1
wrapt==1.12.1
xarray==0.16.2
xlrd==1.1.0
xlwt==1.3.0
yapf==0.30.0
zipp==3.4.0
zope.interface==5.2.0

jupyter labextension list

JupyterLab v3.0.4
/home/bobc/.local/share/jupyter/labextensions
        jupyter-matplotlib v0.8.2 enabled OK
        @jupyter-widgets/jupyterlab-manager v3.0.0 enabled OK (python, jupyterlab_widgets)
        @ryantam626/jupyterlab_code_formatter v1.4.1 enabled OK (python, jupyterlab-code-formatter)
        @jupyter-server/resource-usage v0.5.0 enabled OK (python, jupyter-resource-usage)

Other labextensions (built into JupyterLab)
   app dir: /home/bobc/.local/share/jupyter/lab
        @krassowski/jupyterlab-lsp v2.1.0 enabled OK

jupyter serverextension list

config dir: /home/bobc/.jupyter
    jupyterlab_code_formatter  enabled
    - Validating...
      X is jupyterlab_code_formatter importable?

Screenshots

JupyterLab_error

Additional context

Running Python 3.8.5 under Ubuntu 20.04 under WSL2 under Windows 10. The rest is turtles all the way down.

Jan 13 '21 16:01 BobCu

Could you run jupyter server extension enable --py jupyterlab_code_formatter and retry?

I think this line was removed from the README by mistake.

Jan 16 '21 12:01 ryantam626

Okay removing it from the README was not a mistake, I just didn't publish the package which I have now. If you upgrade to 1.4.2, it should automatically do this and work.

Jan 16 '21 12:01 ryantam626

I too have been trying to get this setup on a JupyterHub/JupyterLab 3.0.5 setup on Ubuntu 18.04. Just tried the 1.4.2 release and still see the unknown version dialog message after restarting JupyterLab.

Jan 16 '21 16:01 sheinb

Doing jupyter server extension enable --py jupyterlab_code_formatter should work

Jan 16 '21 22:01 alanzhong

I did try that based on the comment above, and it seems like things are installed correctly:

jupyter@jupyterhub:~$ jupyter server extension list

Config dir: /opt/tljh/user/etc/jupyter
    jupyter_lsp enabled
    - Validating jupyter_lsp...
      jupyter_lsp 1.0.0 OK
    jupyterlab enabled
    - Validating jupyterlab...
      jupyterlab 3.0.5 OK
    jupyterlab_code_formatter enabled
    - Validating jupyterlab_code_formatter...
      jupyterlab_code_formatter 1.4.2 OK
    jupytext enabled
    - Validating jupytext...
      jupytext 1.9.1 OK
    nbclassic enabled
    - Validating nbclassic...
      nbclassic  OK

Config dir: /usr/local/etc/jupyter

And yet the dialog still pops up with the message:

Unable to find server plugin version, this should be impossible,open a GitHub issue if you cannot figure this issue out yourself.

Jan 17 '21 01:01 sheinb

JupyterHub starts the underlying server differently to how JupyterLab is now started under the hood (I think only since JL 3) . I just spent a whole day diving into this difference and found no easy fix. Anyone using the JupyterHub would need to wait for JupyterHub/JupyterLab people to update their code unfortunately.

For context here is what I found (which is entirely possible to be wrong since I don't have intimate knowledge of JupyterHub/JupyterLab internals):

JupyterHub spawn jupyter notebook server (which coincidentally supports lab somehow?) via https://github.com/jupyterhub/jupyterhub/blob/master/jupyterhub/singleuser/app.py ,it modifies login and logout handler to provide JupyterHub's login/logout experience I blieve.
JupyterLab 3 now something from https://github.com/jupyter-server/jupyter_server or https://github.com/jupyterlab/jupyterlab_server which automatically loads the server extension for you, this behaviour is not replicated to the notebook.notebookapp.NotebookApp class
I am unable to pass JupyterLab 3's app classes into the JupyterHub singleuser script via JUPYTERHUB_SINGLEUSER_APP env var, as the interface just seems to be different and will blow up when trying to apply the mixins.

I think the question now is what to pass into JUPYTERHUB_SINGLEUSER_APP env var and also what changes has to be done on JupyterHub/JupyterLab itself to support this..

Jan 18 '21 09:01 ryantam626

The solution for me is here: https://github.com/jupyterhub/jupyterhub/pull/3329/files Just add the env var to your dockerfile

Jan 19 '21 02:01 s-rog

@s-rog Any idea where the best place to do that if I've installed JupyterHub on a VM, where each user logs into their own account?

Jan 19 '21 02:01 sheinb

I'm not sure as I'm running jupyterhub on k8s where each lab instance is spawned from a docker image

Jan 19 '21 03:01 s-rog

@sheinb perhaps this is helpful? https://github.com/krassowski/jupyterlab-lsp/issues/375#issuecomment-761078622

Jan 19 '21 06:01 s-rog

Thanks for the link. I tried this addition but it prevented my kernels from starting after restarting my TLJH hub. I do have LSP installed, but it seems to work properly (although I'm missing file path completion :-()

Jan 19 '21 07:01 sheinb

Could you run jupyter server extension enable --py jupyterlab_code_formatter and retry?

The above line seems to have resolved the popup warning. Still testing.

Jan 19 '21 18:01 BobCu

The command works fine and the server extension list also indicates it’s installed:

(base) root@jupyterhub:~# jupyter server extension enable --py jupyterlab_code_formatter
Enabling: jupyterlab_code_formatter
- Writing config: /opt/tljh/user/etc/jupyter
    - Validating jupyterlab_code_formatter...
      jupyterlab_code_formatter 1.4.2 OK
    - Extension successfully enabled.

…but the dialog still shows up. You can see from above that this is on a TLJH deployment.

On Jan 19, 2021, at 1:06 PM, BobCu [email protected] wrote:

Could you run jupyter server extension enable --py jupyterlab_code_formatter and retry?

The above line seems to have resolved the popup warning. Still testing.

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/ryantam626/jupyterlab_code_formatter/issues/193#issuecomment-763021654, or unsubscribe https://github.com/notifications/unsubscribe-auth/ACSZXGDTIVLQHM7DE2BH4PDS2XC2FANCNFSM4WBB6C3Q.

Jan 19 '21 20:01 sheinb

One oddity: The initial run failed due to /usr/etc not existing on my system, which I created globally writable. After successful installation, the file /usr/etc/jupyter/jupyter_server_config.d/jupyterlab_code_formatter.json had been created.

Shouldn't that file have been created in my user-local Jupyter config area, ~/.jupyter?

Jan 19 '21 20:01 BobCu

One oddity: The initial run failed due to /usr/etc not existing on my system, which I created globally writable. After successful installation, the file /usr/etc/jupyter/jupyter_server_config.d/jupyterlab_code_formatter.json had been created.

Shouldn't that file have been created in my user-local Jupyter config area, ~/.jupyter?

I am not really sure.

I have tested with this and it seems to work, I was literally one step away when I tested this last week :facepalm:

# get a shell with jupyter hub
docker run -p 8000:8000 -it --name jupyterhub jupyterhub/jupyterhub bash

# install stuff
pip install jupyterlab black isort jupyterlab_code_formatter

# add user
useradd -m ryan

# generate config
jupyterhub --generate-config

# simple auth for testing
echo "c.JupyterHub.authenticator_class = 'jupyterhub.auth.DummyAuthenticator'" >> jupyterhub_config.py
echo "c.DummyAuthenticator.password = 'abc'" >> jupyterhub_config.py

# spin jupyter hub up
JUPYTERHUB_SINGLEUSER_APP='jupyter_server.serverapp.ServerApp' jupyterhub -f jupyterhub_config.py

# go to localhost:8000 on your host
# login with whatever user you created (`ryan`) in my case, password is `abc`
# http://localhost:8000/user/ryan/ should just say `A Jupyter Server is running.` which is where i got confused last week (replace name of user if needed)
# http://localhost:8000/user/ryan/lab should have a usable lab instance now (replace name of user if needed)

Jan 23 '21 11:01 ryantam626

I am having this issue using 1.3.8 version of plugin&extension. (1.3.6 also tried)

pip install jupyterlab_code_formatter==1.3.6 && \
jupyter serverextension enable --py jupyterlab_code_formatter && \
jupyter server extension enable jupyterlab_code_formatter --user && \ # tried this too
jupyter labextension install @ryantam626/[email protected] && \

My jupyterlab version is 2.2.9. I am not using 1.4 version of jupyterlab_code_formatter because it update my jupterlab to 3, which is something I don't want yet.

At first start, (after showing issue error) jupyter serverextension list does not show formatter as enabled. After a jupyter serverextension enable --py jupyterlab_code_formatter in terminal, it mark it as enabled, but nothing changes. Error still pop up, ant obviously the tool is not available.

I also tried 1.3.2 same behaviour without pop up.

No jupyterhub involved, just jupyterlab

Feb 02 '21 08:02 masip85

Updated our TLJupyterHub+JupyterLab to 3.0.7 and reinstalled the extension, and no more "unknown version" dialog message and the format cell appears as expected in the drop down!

Feb 05 '21 17:02 sheinb

A couple of cases that produce this error:

not having "jupyterlab_code_formatter": true in ServerApp.jpserver_extensions
if you're formatting R code, not having R and the R package languageserver installed correctly (double check env vars like $R_HOME and $R_LIBS_SITE and be sure rpy2 is using the same R environment)

Feb 06 '21 00:02 ariutta

Just sharing my experience in case it might help others: No matter what I did, I kept getting the pop up error: Unable to find server plugin version, this should be impossible,open a GitHub issue if you cannot figure this issue out yourself. I tried re-installing the plugin, updating my jupyterlab to version 3+, manually enabling it via jupyter server extension enable --py jupyterlab_code_formatter.

In the end, I delete the conda cache via conda clean --all --force-pkgs-dir (the --force-pkgs-dir was essential), and then reinstalled the plugin, and everything just worked.

Mar 10 '21 13:03 ma-sadeghi

Thanks all! I just updated my pip install --user version of JupyterLab and had to set this in ~/.jupyter/jupyter_server_config.py:

c.ServerApp.jpserver_extensions = {
    "jupyterlab": True,
    "jupyterlab_code_formatter": True,
}

The ~/.jupyter/jupyter_server_config.py is necessary (and was not shown in the commented-out default value), because otherwise jupyter lab will not run at all.

Mar 26 '21 12:03 ast0815

The solution for me is here: https://github.com/jupyterhub/jupyterhub/pull/3329/files Just add the env var to your dockerfile

I found that is used for Linux '-' do you know how to solve in window

Apr 25 '21 03:04 nguyentuanngoc21

jupyter server extension enable --py jupyterlab_code_formatter --user

Works for me.

Jul 08 '21 04:07 GF-Huang

Could you run jupyter server extension enable --py jupyterlab_code_formatter and retry?

I think this line was removed from the README by mistake.

I have the same error as OP. Running your commands gives an error - https://i.imgur.com/UUEo236.png

Aug 12 '21 23:08 roboserg

Had a similar issue when following the documentation together with a Jupyter Lab 3.2.2 install on a macbook M1, jupyter server extension enable --py jupyterlab_code_formatter fixed it. The plugin works fine now.

Nov 23 '21 10:11 deKeijzer

A couple of cases that produce this error:

not having "jupyterlab_code_formatter": true in ServerApp.jpserver_extensions

if you're formatting R code, not having R and the R package languageserver installed correctly (double check env vars like $R_HOME and $R_LIBS_SITE and be sure rpy2 is using the same R environment)

Maybe it is caused by R, because just after the installation of R in conda environment it occurs.

Dec 08 '21 07:12 DatumWorld

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Jupyterlab Code Formatter Error Unable to find server plugin version

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