ISE on any request

Status changed to 'Confirmed' because the bug affects multiple users.

I'm also encountering this issue, I probed a bit and noticed that the issue seems to be related to a mismatch between the fastapi version that is shipped in Ubuntu (0.63.0) and the starlette version (0.18.0).

As of changelog, officially fastapi started supporting starlette 0.18.0 only as of 0.76.0 (i.e. here https://fastapi.tiangolo.com/release-notes/#0760). For fastapi 0.63.0 the starlette requirement is 0.13.6 (i.e. here https://github.com/tiangolo/fastapi/blob/0.63.0/pyproject.toml#L35)

There also seem to be issues with uvicorn, for example fastapi 0.63.0 depends on uvicorn between 0.12.0 and 0.14.0 (i.e. here https://github.com/tiangolo/fastapi/blob/0.63.0/pyproject.toml#L93) but the system installed version is 0.15.0.

Bumping fastapi to a newer version should fix the package, as the bug above it can't really be used right now

I also confirm that this bug renders the current installation of fastapi in Ubuntu 22.04 unusable. I have used a virtual environment to install a new version of fastapi while using the rest of the packages from the system as follows:

# python3 -m venv --system-site-packages
# pip install fastapi==0.76

I then have tested that with the following self-contained test works fine:
import requests

import threading
import unittest
from time import sleep
import uvicorn.server

from fastapi import FastAPI

app = FastAPI()

@app.get("/ping")
def get_object() :
    return {"ping": "OK"}

class FastAPITest(unittest.TestCase):
    server: uvicorn.server.Server = None

    def __init__(self, args):
        super().__init__(args)

    @classmethod
    def setUpClass(cls):
        from uvicorn.config import Config
        from uvicorn import Server
        uvicorn_config = Config(app, port=8888, host="localhost")
        FastAPITest.server = Server(config=uvicorn_config)
        threading.Thread(target=FastAPITest.server.run).start()
        sleep(1)

    @classmethod
    def tearDownClass(cls):
        FastAPITest.server.should_exit = True
        sleep(1)

    def test_ping(self):
        requests.get("http://localhost:8888/ping")

As previous comment said, version 0.76 of fastapi would be compatible with the installed versions of both starlette and uvicorn and will solve the issue.

@Sandro Tosi: I have subscribed you to this bug since you seem to be the maintainer of the package. My apologies if that's not the case.

i maintain fastapi for debian, not for ubuntu, so i'm not the right person to ask/escalate issues to.

Thank you Sandro for the answer.
In the meantime I see that Ubuntu 22.10 which ships python3-fastapi 0.74.1-1 while using the same versions of python3-starlette and python3-uvicorn as Ubuntu 22.04 is working properly. So I guess that the minimum effort would be to also ship python3-fastapi 0.74.1-1 in Ubuntu 22.04.

I've prepared a SRU for this bug. It contains two upstream commits that make the package work with the starlette version in jammy. All the information from the SRU template are already answered above, so I am not copying them here again.

Thank you very much Rhonda for this SRU. I can help with testing, but I am afraid I don't know how to test your changes. Is there a deb package somewhere that can be installed?

Thank you!

Thanks Enrique. I tried to follow the SRU guide lines but my upload was rejected, and I am unsure what the reason for that was because the errors I get were confusing. Source-only upload got a reject message "Mismatch in binaryfullness", but with the binary package included dput didn't allow me to upload at all. I'm still trying to figure this out.

this bug is missing the SRU information from the description

Timo, can you please elaborate what is missing? Because it's there. If you are just referring that it doesn't use the template then ... sorry to not followed the bureocratic bits to the detail, I'll do that now. I can though understand that not having done that directly would have left more work on your shoulders, I was under the impression that all bits are already in here (and it's not like there are hundreds of comments, so ...)

[ Impact ]

The package can't be used at all in its current state because it doesn't work with one of its central dependencies. It creates a backtrace as seen in the original bug description on simple usage cases.

The bugfix makes the package compatible with the newer version of the dependency.

[ Test Plan ]

 * detailed instructions how to reproduce the bug

See the example code in the bug description, but for convenience I paste it here again:

Create a file "fastapi-test.py" with the following code:

-----
from fastapi import FastAPI

app = FastAPI()

@app.get("/")
async def root():
    return {"Status": "ok"}
-----

Then run that file with python interpreter.

[ Where problems could occur ]

 * Think about what the upload changes in the software. Imagine the change is
   wrong or breaks something else: how would this show up?

The package isn't usable at all right now. It can't get worse than that, frankly speaking.

 * This must '''never''' be "None" or "Low", or entirely an argument as to why
   your upload is low risk.

Well, actually what regression risk could there be for a package not usable at all right now? I would very much assert that this covers a clear "None" because even if the fix wouldn't work (which it does) the package still would just not work and couldn't be in a worse state.

[ Other Info ]

 * Anything else you think is useful to include

I really thought the bug description and the description of the patch should be self-explenatory, and I'm sorry that this assumption seemingly was wrong. My bad.

Hello Pavel, or anyone else affected,

Accepted fastapi into jammy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/fastapi/0.63.0-2ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-jammy to verification-done-jammy. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-jammy. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

I have tried with one application that uses fastapi and it seems it is working fine. I have not tested it thoroughly but at least calling a couple of API methods is working fine.
Thank you very much for fixing this!