bug with matplolib qt backend (% matplolib qt) #17115
Description
Applies To
- Notebooks (.ipynb files)
- Interactive Window and/or Cell Scripts (.py files with #%% markers)
What happened?
when a try to make a graph with qt backend with matplotlib, it result in a stuck windows with no graph in it. when you use the inline backend, everthing work well. similar resulat is optained when you use tk backend. exemple of code tried :
import numpy as np
import matplotlib.pyplot as plt
%matplotlib qt
range_1 = np.array([1,2,3])
fig,ax = plt.subplots()
ax.plot(range_1,range_1)
VS Code Version
1.106.0 insider and 1.105.1
Jupyter Extension Version
2025.9.1 and 2025.9.0
Jupyter logs
11:15:38.603 [debug] Restart kernel command handler for Untitled-1.ipynb
11:15:39.842 [debug] restart the kernel, options.disableUI=false for Untitled-1.ipynb
11:15:39.842 [info] Restart requested Untitled-1.ipynb
11:15:39.843 [debug] Cancel pending cells
11:15:39.844 [debug] Dispose Kernel process 19832.
11:15:39.862 [info] Process Execution: c:\WINDOWS\System32\taskkill.exe /F /T /PID 19832
11:15:39.881 [info] Process Execution: ~\Documents\Data_travail\Programme\Jupiter-notebook\venv\Scripts\python.exe -c "import ipykernel; print(ipykernel.__version__); print("5dc3a68c-e34e-4080-9c3e-2a532b2ccb4d"); print(ipykernel.__file__)"
11:15:39.952 [debug] Launching kernel .jvsc74a57bd04e19e84e528612ce35f54804f8260a7dc673fb1b3e9fb50b712bccd0c7df9928.~\Documents\Data_travail\Programme\Jupiter-notebook\venv\Scripts\python.exe.~\Documents\Data_travail\Programme\Jupiter-notebook\venv\Scripts\python.exe.-m#ipykernel_launcher for Untitled-1.ipynb in ~\Documents\Data_travail\Programme\Jupiter-notebook with ports 9001, 9000, 9004, 9002, 9003
11:15:39.957 [trace] Got a response of 5464 for INITIALIZE_INTERRUPT:6
11:15:39.982 [info] Process Execution: ~\Documents\Data_travail\Programme\Jupiter-notebook\venv\Scripts\python.exe -m ipykernel_launcher --f=~\AppData\Roaming\jupyter\runtime\kernel-v30be03ad34b3aca027528aeb035bfee9f1a9ac9e0.json
> cwd: ~\Documents\Data_travail\Programme\Jupiter-notebook
11:15:39.982 [debug] Kernel process 22596.
11:15:40.003 [debug] Waiting for Raw Session to be ready in postStartRawSession
11:15:40.003 [debug] Waiting for Raw session to be ready, status: connected
11:15:40.003 [trace] Raw session connected
11:15:40.005 [debug] Waited for Raw session to be ready & got status: connected
11:15:40.006 [debug] Successfully waited for Raw Session to be ready in postStartRawSession
11:15:40.006 [debug] Kernel status is 'unknown' before requesting kernel info and after ready
11:15:40.006 [debug] Sending request for kernelInfo
11:15:40.422 [debug] KernelProcess Exited 19832, Exit Code - 1
11:15:40.432 [debug] Disposed Kernel process 19832.
11:15:40.433 [trace] ipykernel version & path 7.0.1, ~\Documents\Data_travail\Programme\Jupiter-notebook\venv\Lib\site-packages\ipykernel\__init__.py for ~\Documents\Data_travail\Programme\Jupiter-notebook\venv\Scripts\python.exe
11:15:40.517 [trace] Did not get a response for requestKernelInfo
11:15:40.517 [debug] Sending request for kernelInfo
11:15:40.992 [debug] Kernel output 22596: To connect another client to this kernel, use:
--existing ~\AppData\Roaming\jupyter\runtime\kernel-v30be03ad34b3aca027528aeb035bfee9f1a9ac9e0.json
11:15:41.023 [trace] Did not get a response for requestKernelInfo
11:15:41.023 [debug] Sending request for kernelInfo
11:15:41.192 [trace] Got response for requestKernelInfo
11:15:41.192 [debug] Successfully completed postStartRawSession after 3 attempt(s) in 1186ms
11:15:41.193 [info] Restarted 70d38168-663c-4c7f-ae11-cf400eda2fb3
11:15:41.194 [trace] Executing silently Code (idle) = import sys as _VSCODE_sys\nprint(_VSCODE_sys.executable); del _VSCODE_sys
11:15:41.208 [trace] Executing silently Code (completed) = import sys as _VSCODE_sys\nprint(_VSCODE_sys.executable); del _VSCODE_sys with 1 output(s)
11:15:41.209 [trace] Started running kernel initialization for Untitled-1.ipynb
11:15:41.209 [trace] Executing silently Code (idle) = try:\nimport ipywidgets as _VSCODE_ipywidgets\nprint("e976ee50-99ed-4aba-9b6b-9dcd5634d07d:IPy
11:15:41.217 [trace] Executing silently Code (completed) = try:\nimport ipywidgets as _VSCODE_ipywidgets\nprint("e976ee50-99ed-4aba-9b6b-9dcd5634d07d:IPy with 0 output(s)
11:15:41.217 [trace] Determined IPyWidgets Version as undefined
11:15:41.217 [trace] Executing silently Code (idle) = def __VSCODE_inject_module():\ndef __VSCODE_call_function(function, callback, data=None):
11:15:41.228 [trace] Executing silently Code (completed) = def __VSCODE_inject_module():\ndef __VSCODE_call_function(function, callback, data=None): with 0 output(s)
11:15:41.229 [debug] Requesting Kernel info
11:15:41.229 [trace] Got Kernel info
11:15:41.229 [trace] End running kernel initialization, now waiting for idle
11:15:41.229 [trace] Waiting for idle on (kernel): 70d38168-663c-4c7f-ae11-cf400eda2fb3 -> idle
11:15:41.229 [trace] Finished waiting for idle on (kernel): 70d38168-663c-4c7f-ae11-cf400eda2fb3 -> idle
11:15:41.229 [trace] End running kernel initialization, session is idle
11:15:41.230 [trace] Registering commtarget jupyter.widget
11:15:44.768 [debug] Handle Execution of Cells 0 for Untitled-1.ipynb
11:15:44.769 [trace] Execute Notebook Untitled-1.ipynb. Step 1
11:15:44.769 [trace] Connect to Kernel Untitled-1.ipynb. Step 2
11:15:44.769 [trace] Connected to Kernel Untitled-1.ipynb. Step 3
11:15:44.769 [trace] executeCell 0. Step 4
11:15:44.770 [trace] Cell Index:0 sent to kernel
11:15:44.773 [trace] Start cell 0 execution @ 1761297344772 (clear output)
11:15:44.773 [debug] Kernel acknowledged execution of cell 0 @ 1761297344772
11:15:45.462 [trace] Cell 0 completed in 0.69s (start: 1761297344772, end: 1761297345462)
11:15:45.462 [trace] Cell 0 executed successfully
11:15:46.709 [debug] Handle Execution of Cells 1 for Untitled-1.ipynb
11:15:46.710 [trace] Execute Notebook Untitled-1.ipynb. Step 1
11:15:46.710 [trace] Connect to Kernel Untitled-1.ipynb. Step 2
11:15:46.710 [trace] Connected to Kernel Untitled-1.ipynb. Step 3
11:15:46.711 [trace] executeCell 1. Step 4
11:15:46.711 [trace] Cell Index:1 sent to kernel
11:15:46.716 [trace] Start cell 1 execution @ 1761297346716 (clear output)
11:15:46.716 [debug] Kernel acknowledged execution of cell 1 @ 1761297346716
11:15:46.941 [trace] Cell 1 completed in 0.224s (start: 1761297346716, end: 1761297346940)
11:15:46.942 [trace] Cell 1 executed successfully
11:15:53.358 [debug] KernelProcess Exited 22596, Exit Code - null
11:15:53.359 [error] Disposing session as kernel process died ExitCode: undefined, Reason:
11:15:53.359 [debug] Dispose Kernel process 22596.
11:15:53.369 [debug] Disposed Kernel process 22596.
11:15:53.371 [trace] Start cell 1 execution @ 1761297346716
11:15:53.398 [trace] Cell 1 completed in -1761297346.716s (start: 1761297346716, end: undefined)Coding Language and Runtime Version
python 3.13.7
Language Extension Version (if applicable)
No response
Anaconda Version (if applicable)
No response
Running Jupyter locally or remotely?
Local