Notebook kernel crashed on Linux systems

[ChromatinRemodeling]

I tried to reproduce the result in simulation.ipynb in a newly installed python3.11 environment. On Windows system everything worked fine, but on Linux systems the notebook kernel will always crash on the following lines:

Is = bm.ones(1000) * 20.  # 100 ms
_ = runner.run(inputs=Is)

This behavior is consistently observed in Colab, as well as in WSL and Ubuntu. For most of the time the error message is:

The Kernel crashed while executing code in the current cell or a previous cell. 
Please review the code in the cell(s) to identify a possible cause of the failure. 
Click [here](https://aka.ms/vscodeJupyterKernelCrash) for more info. 
View Jupyter log for further details.

But for once or twice there is a JAX-related error, which I am unable to reproduce.

[Routhleck]

Could you provide the Jupyter log?

[ChromatinRemodeling]

Sure.

On WSL:

Visual Studio Code (1.99.3, wsl, desktop)
Jupyter Extension Version: 2025.3.0.
Python Extension Version: 2025.4.0.
Pylance Extension Version: 2025.4.1.
Platform: linux (x64).
Home = /home/trli
Temp Storage folder ~/.vscode-server/data/User/globalStorage/ms-toolsai.jupyter/version-2025.3.0
Workspace folder ~/lab/BrainPy
15:55:26.507 [info] Starting Kernel (Python Path: ~/lab/BrainPy/.pixi/envs/default/bin/python, VirtualEnv, 3.11.12) for '~/lab/BrainPy/simulation.ipynb' (disableUI=true)
15:55:27.205 [info] Process Execution: ~/lab/BrainPy/.pixi/envs/default/bin/python -m pip list
15:55:27.218 [info] Process Execution: ~/lab/BrainPy/.pixi/envs/default/bin/python -c "import ipykernel; print(ipykernel.__version__); print("5dc3a68c-e34e-4080-9c3e-2a532b2ccb4d"); print(ipykernel.__file__)"
15:55:27.227 [info] Process Execution: ~/lab/BrainPy/.pixi/envs/default/bin/python -m ipykernel_launcher --f=/run/user/1000/jupyter/runtime/kernel-v306402bdd2757f65721ad1c4adc721a50a10861b2.json
    > cwd: ~/lab/BrainPy
15:55:29.193 [info] Kernel successfully started
15:55:29.205 [info] Process Execution: ~/lab/BrainPy/.pixi/envs/default/bin/python /home/~/.vscode-server/extensions/ms-toolsai.jupyter-2025.3.0-linux-x64/pythonFiles/printJupyterDataDir.py
15:55:30.011 [error] Widget Error: Failed to access CDN https://unpkg.com/ after 0 attempt(s), TypeError: Failed to fetch
15:56:18.307 [error] Disposing session as kernel process died ExitCode: undefined, Reason: 
15:56:24.864 [info] Restart requested ~/lab/BrainPy/simulation.ipynb
15:56:24.869 [warn] Cancel all remaining cells due to dead kernel
15:56:24.884 [info] Process Execution: ~/lab/BrainPy/.pixi/envs/default/bin/python -c "import ipykernel; print(ipykernel.__version__); print("5dc3a68c-e34e-4080-9c3e-2a532b2ccb4d"); print(ipykernel.__file__)"
15:56:24.897 [info] Process Execution: ~/lab/BrainPy/.pixi/envs/default/bin/python -m ipykernel_launcher --f=/run/user/1000/jupyter/runtime/kernel-v30b6b13b27902705e04f4629999cf1e196497217d.json
    > cwd: ~/lab/BrainPy
15:56:25.335 [info] Restarted 2d2a6462-78b3-44b0-8465-6954e8466945

[ChromatinRemodeling]

On Colab: app.log

[Routhleck]

Ok i see, Could you provide your hardware info and software version

[ChromatinRemodeling]

On Ubuntu 24.04:

Visual Studio Code (1.99.3, undefined, desktop)
Jupyter Extension Version: 2025.3.0.
Python Extension Version: 2025.4.0.
Pylance Extension Version: 2025.4.1.
Platform: linux (x64).
Home = /home/chromatin_remodeling
Temp Storage folder ~/.config/Code/User/globalStorage/ms-toolsai.jupyter/version-2025.3.0
Workspace folder ~/newData/BrainPy/Brainpy
19:05:25.924 [info] Starting Kernel (Python Path: ~/newData/BrainPy/Brainpy/.pixi/envs/default/bin/python, VirtualEnv, 3.10.17) for '~/newData/BrainPy/Brainpy/src/simulation.ipynb' (disableUI=true)
19:05:26.038 [info] Process Execution: ~/newData/BrainPy/Brainpy/.pixi/envs/default/bin/python -c "import ipykernel; print(ipykernel.__version__); print("5dc3a68c-e34e-4080-9c3e-2a532b2ccb4d"); print(ipykernel.__file__)"
19:05:26.044 [info] Process Execution: ~/newData/BrainPy/Brainpy/.pixi/envs/default/bin/python -m ipykernel_launcher --f=/run/user/1001/jupyter/runtime/kernel-v333068a3e4aa9ddf5cb47b860757b5b4bde603d3e.json
    > cwd: ~/newData/BrainPy/Brainpy/src
19:05:26.056 [info] Process Execution: ~/newData/BrainPy/Brainpy/.pixi/envs/default/bin/python -m pip list
19:05:26.506 [info] Kernel successfully started
19:05:26.517 [info] Process Execution: ~/newData/BrainPy/Brainpy/.pixi/envs/default/bin/python /home/~/.vscode/extensions/ms-toolsai.jupyter-2025.3.0-linux-x64/pythonFiles/printJupyterDataDir.py
19:05:41.099 [error] Disposing session as kernel process died ExitCode: undefined, Reason:

Installed packages:

brainpy           2.6.0.post20250420
brainstate        0.1.0.post20250420
braintaichi       0.0.4
brainunit         0.0.8
jax               0.5.3
jaxlib            0.5.3
...

The full list is here:

Ubuntu.txt

[ChromatinRemodeling]

I am using Dell Inc. Precision 3660 with 13th Gen Intel® Core™ i9-13900K × 32 and RTX 4090 here.

[ChromatinRemodeling]

On WSL, python 3.11.12:

brainevent                0.0.1.post20250422
brainpy                   2.6.0.post20241205
brainstate                0.1.0.post20250423
braintaichi               0.0.4
brainunit                 0.0.8
jax                       0.5.2
jax-cuda12-pjrt           0.5.1
jax-cuda12-plugin         0.5.1
jaxlib                    0.5.1
...

Full list:

WSL.txt

I am using Lenovo Legion R9000X2021R with AMD Ryzen 7 5800H with Radeon Graphics and RTX 3060 here. The WSL version is Ubuntu 24.04.

[Routhleck]

I notice "No CUDA driver API detected" in the logs.
Have you properly configured the NVIDIA driver and CUDA toolkit in Linux?

Can you successfully run nvidia-smi and nvcc -V and get normal outputs from both commands?

[ChromatinRemodeling]

I can get normal outputs on my WSL. I cannot get normal outputs on my Ubuntu computer because I haven't configured it. But I suppose the problem isn't caused by GPU-related issues because the bm.set_platform('cpu') at the beginning.

[Routhleck]

I tested and found that the problem is with JAX version 0.5.3, which seems to be incompatible with BrainTaichi, causing a memory overflow bug. I recommend downgrading JAX to 0.4.38 .

pip install jax==0.4.38

[ChromatinRemodeling]

I tried to downgrade JAX on WSL and Ubuntu, but to no avail. The bug persists. The "No CUDA driver API detected" log is from Colab, where I use only CPU. I also tried to downgrade JAX on Colab, but other pre-installed packages prevented me from doing so.

I guess there is really a memory overflow. I wonder if there is any technique for me to find out the overflow myself? And maybe you can tell me given jax==0.4.38, which version of brainevent, brainpy, brainstate, braintaichi, and brainunit are you using? I now have trouble finding a working combination.

[ChromatinRemodeling]

Also, I think I found something interesting. I saw that in brainpy's package metadata, jaxlib[cuda12_pip] is still being specified. But according to the Changelog of JAX, the cuda12_pip extra for jax has been removed in 0.6.0. This may or may not be relevant to the failing transition to jax0.6.0.

I tried to edit the metadata like this:

Requires-Python: >=3.9
Description-Content-Type: text/markdown
License-File: LICENSE
Requires-Dist: numpy (>=1.15)
Requires-Dist: tqdm
Provides-Extra: cpu
Requires-Dist: jax (<=0.5.2,>=0.4.13) ; extra == 'cpu'
Requires-Dist: jaxlib (<=0.5.2,>=0.4.13) ; extra == 'cpu'
Requires-Dist: numba ; extra == 'cpu'
Requires-Dist: braintaichi ; extra == 'cpu'
Provides-Extra: cpu_mini
Requires-Dist: jax (<=0.5.2,>=0.4.13) ; extra == 'cpu_mini'
Requires-Dist: jaxlib (<=0.5.2,>=0.4.13) ; extra == 'cpu_mini'
Provides-Extra: cuda12
Requires-Dist: jax[cuda12] (<=0.5.2,>=0.4.13) ; extra == 'cuda12'
Requires-Dist: jaxlib (<=0.5.2,>=0.4.13) ; extra == 'cuda12'
Requires-Dist: numba ; extra == 'cuda12'
Requires-Dist: braintaichi ; extra == 'cuda12'
Provides-Extra: cuda12_mini
Requires-Dist: jax[cuda12] (<=0.5.2,>=0.4.13) ; extra == 'cuda12_mini'
Requires-Dist: jaxlib ; extra == 'cuda12_mini'
Provides-Extra: tpu
Requires-Dist: jaxlib[tpu] ; extra == 'tpu'
Requires-Dist: numba ; extra == 'tpu'

And it removed the warnings in pip install brainpy. Although, the simulation still cannot be run.

Also, I guess the dependency_links.txt in the package can also be removed because it is deprecated.

[Routhleck]

Sorry for the delayed response. Through GDB debugging, I found that the issue occurs when BrainTaichi loads the kernel module, not during the execution of the kernel itself. We will fix this issue soon and release a new version of BrainTaichi.

In the meantime, I’d like to share a workaround using an older stable version. You can install it by running the following command:

pip install jax[cuda12]==0.4.38
pip install brainpy==2.6.0.post20241025
pip install brainpylib
pip install taichi==1.7.0

Hope this helps.

[ChromatinRemodeling]

Thanks! The older stable version works smoothly.

[Routhleck]

Hi, we already release a new BrainTaichi version, you can try it with the latest brainpy.

pip install brainpy -U
pip install jax[cuda12]==0.4.38
pip install taichi==1.7.3