UI terminates or "File not found"

[efabgp]

System: Windows 11
Python Version: tried 3.11.8 and 3.13.3
Corporate notebook with corporate proxy requirements but our own uvicorn applications always worked locally.

I followed the instructions of the quickstart with UI here: https://sqlmesh.readthedocs.io/en/stable/quickstart/ui/
What I did:

• create a fresh venv and activate it
• pip install sqlmesh[web]
• sqlmesh init duckdb
• sqlmesh ui
• navigate to http://127.0.0.1:8000

With Python 3.13

The UI is loading and I can see the whole page. But then, network errors are reported. On the terminal I can see that uvicorn stops and the application terminates. There is no error message, I only see INFO level logging logging HTTP 200 access to some resources. The last is /api/models. I figure something goes wrong there and the server crashes but I don't get any error messages.

after that, I get back to my prompt, the application is terminated.

With Python 3.11

The UI is not crashing and the complete UI page is loading. But I got the error
Failed to load a cache entry 'models__full_model': No module named 'pathlib._local'; 'pathlib' is not a package in the terminal.
So I just installed pathlib and actually got rid of the message.
But when I try to open any file in the UI, the editor window just shows "File not found". After 30 seconds I also receive UI errors about timeouts:

But the application does not terminate and I get no errors on the terminal.

Is there a specific Python version that I should use? Or something else I could try to make the UI run properly?

[erindru]

Hi @efabgp , thanks for raising. The UI has a bunch of known issues on Windows.

Also, the error you got with pathlib is suspicious since pathlib is meant to be bundled with Python as part of its standard library.

Have you considered trying the VSCode Extension instead?

[efabgp]

Hi @erindru, thanks for the quick response!
I just installed the VSCode Extension and it seems to work great, thank you! I know, the pathlib thing was weird.
But with the VSCode Extension I did not come across issues until now. I will continue checking out what SQLMesh can do for us, thanks :-)

I observed that with Python3.13, not even the CLI is working. sqlmesh plan returns after a few seconds with no output at all. It seems to work fine with Python3.11. Should I open another issue for that or is that already known?

[erindru]

Are you running SQLMesh in a WSL2 container or on the Windows native command prompt?

Something sounds off in your environment

[efabgp]

Windows native command prompt in a Windows PowerShell, Python13 installed via Chocolatey. So you say SQLMesh should run with Python3.13? I didn't have any issues with my Python environments until now.

[stephen-elves]

Sorry so is the response that SQLMesh UI and CLI are brokne on the version of Python now shipped with windows?
And to use the VS Code extension instread.
But the onlt quickstarts for SQLMesh are:

1. CLI
2. Notebooks
3. UI

NO Vs code quickstart, because that's pretty jank......