Error mesage: 'int' object has no attribute 'items' when run example code

[leakedby]

Description

Python version: 3.12.1 with virtualenv
NiceGUI version: latest

I got error message: 'int' object has no attribute 'items'.
When run example code from home page.
Tried downgrade version but still got error message.

Code:

from nicegui import ui

ui.label('Hello NiceGUI!')

ui.run()

Error message:

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/uvicorn/protocols/http/httptools_impl.py", line 435, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
    return await self.app(scope, receive, send)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/fastapi/applications.py", line 1054, in __call__
    await super().__call__(scope, receive, send)
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/starlette/applications.py", line 116, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/starlette/middleware/errors.py", line 176, in __call__
    response = await self.handler(request, exc)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/nicegui/nicegui.py", line 142, in _exception_handler_500
    return client.build_response(request, 500)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/nicegui/client.py", line 119, in build_response
    return templates.TemplateResponse('index.html', {
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/starlette/templating.py", line 224, in TemplateResponse
    return _TemplateResponse(
           ^^^^^^^^^^^^^^^^^^
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/starlette/templating.py", line 39, in __init__
    super().__init__(content, status_code, headers, media_type, background)
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/starlette/responses.py", line 38, in __init__
    self.init_headers(headers)
  File "/Users/james/HelloW/Crawl/.venv/lib/python3.12/site-packages/starlette/responses.py", line 57, in init_headers
    for k, v in headers.items()
                ^^^^^^^^^^^^^
AttributeError: 'int' object has no attribute 'items'

[rodja]

Could you share the full exception stack? The message "During handling of the above exception, another exception occurred" hints for something else going on.

[rodja]

You also cross-posted on Reddit and StackOverflow if I'm not mistaken.

[DavidLeBonk]

Could you share the full exception stack? The message "During handling of the above exception, another exception occurred" hints for something else going on.

https://discord.com/channels/1089836369431498784/1189464339007156236/1189464339007156236

I had the same error and in the attached message I have a .txt attached with a full traceback

[DavidLeBonk]

a .txt attached with a full traceback

Here is the txt in question so yall don't gotta hop platforms

traceback.txt

[falkoschindler]

Thanks a lot, @DavidLeBonk!
It would be interesting to bisect since which NiceGUI version the error occurs. The traceback mentions the TemplateResponse, but I don't recall recent changes to the templating implementation. 🤔

[DavidLeBonk]

Wishing ya the best 👍

[falkoschindler]

Yes! I found the root cause of the problem:
The API for Starlette's templates.TemplateResponse() introduced a new positional argument request (see encode/starlette#2191). This causes our status code to be interpreted as headers dictionary, which fails.

[DavidLeBonk]

Ah, who doesn't love it when a child library changes something seemingly small and it breaks the everything.

npm moment

[DavidLeBonk]

Also @falkoschindler should I delete the discord post now to avoid clutter?

[falkoschindler]

@DavidLeBonk No, I think it's good to keep a reference to this issue so that other users can find it more easily.

[falkoschindler]

I noticed that the change in Starlette wasn't an issue, because FastAPI required an older version. Just last night FastAPI 0.108.0 was released, upgrading to Starlette >=0.29.0,<0.33.0.

I already tried adding the request argument, but then there are other exceptions popping up.

[rodja]

We just released 1.4.8 with the needed fix.

[DavidLeBonk]

Nice, love to see the quick fixes ^-^