PyInstaller fails to pack a simple NiceGui script

Description

Can someone help me troubleshoot why I can't pack anything? I'm using Python 3.13 on Windows 23H2.
I'm trying to package my app with:

nicegui-pack --onefile --name "myapp" main.py

main.py

from nicegui import native, ui

ui.label('Hello from PyInstaller')

ui.run(reload=False, port=native.find_open_port())

But I get this error when launching the dist/myapp.exe:

Running it directly with python .\main.py works:

[falkoschindler]

Hm... Can anyone with a Windows machine reproduce this problem?

I found a workaround by downgrading to python 3.9

[evnchn]

Hm... Can anyone with a Windows machine reproduce this problem?

Cannot replicate. Works on my machine.

Python 3.12.5, NiceGUI 2.13.0, PyInstaller 6.12.0

Would say: your port is 8080, but if you do ui.run(reload=False, port=native.find_open_port()), then it should find a port from 8000 to 8099, using the first one usable. Unless all ports from 8000 to 8079 are occupied on your machine, you may have visited the wrong web server.

Regardless, @norlatif we probably need more screenshots like the terminal output to work further on this.

[weinibuliu]

I also cannot replicate. It works on my machine.

Windows10 21H2 LTSC(19044.5608)
Python 3.12.7, NiceGUI 2.13.0, PyInstaller 6.12.0

[evnchn]

1. Why it is port 8080 is still a mystery
2. Internal Server Error rarely shows up. Last time I seen it, I was messing with the internals of NiceGUI for the custom error screen

So yeah, many unsolved mysteries. Maybe you packed a non-NiceGUI script? Given VSCode console only works on the current directory of the opened windows unless you do cd, could be an explanation...