FastAPI 0.100.0 breaks gradio

[thiagohersan]

Describe the bug

I had to restart some containers on Huggingface spaces and afterwards none of them would work.
It was strange because most of my few dependencies were pinned.

What would happen:
Examples would run and cache, but Interface would show Error right away whenever I interacted with any of the UI elements. Even hitting the "clear" button would throw an error on the UI, but no error on the python logs.

Same thing happened on Docker spaces if I forced image rebuild.

When debugging locally I noticed a similar situation, no errors on the command line, but I did notice there were errors on my browser console:

POST http://127.0.0.1:7860/run/predict 422 (Unprocessable Entity)

After some googling, I guessed it had to do with FastAPI and their new release, so I pinned FastAPI to version 0.99.0 and all is fine again.

Have you searched existing issues? 🔎

• I have searched and found no existing issues

Reproduction

Install gradio 3.23.0 (although same error occurs in 3.16.2) via conda and run a minimal example.
Even the Interfaces example bugs out:

import gradio as gr

def greet(name):
    return "Hello " + name + "!"

demo = gr.Interface(fn=greet, inputs="text", outputs="text")
    
if __name__ == "__main__":
    demo.launch()   

Screenshot

Logs

No Python errors.

This is the JavaScript error:

POST http://127.0.0.1:7860/run/predict 422 (Unprocessable Entity)

Full log:

index.37b24c07.js:4
POST http://127.0.0.1:7860/run/predict 422 (Unprocessable Entity)
Fr @ index.37b24c07.js:4
(anonymous) @ index.37b24c07.js:4
N @ index.37b24c07.js:4
k @ index.37b24c07.js:4
ue @ Blocks.svelte:303
ze @ Blocks.svelte:298
(anonymous) @ Blocks.svelte:342
(anonymous) @ index.37b24c07.js:4
zr @ index.37b24c07.js:4
_ @ Button.svelte:12
(anonymous) @ index.37b24c07.js:4
zr @ index.37b24c07.js:4
c @ Button.svelte:11

System Info

Gradio 3.23.0 (and 3.16.2)
Mac OS Ventura and Linux Ubuntu 20
Chrome 114

Severity

I can work around it

[thiagohersan]

I am guessing the latest PR pulled into main (#4835) will fix this....

[freddyaboulton]

Hi @thiagohersan ! You should either install the latest gradio (3.36.1) or pin pydantic at version 1 (pip install pydantic==1.*)

[thiagohersan]

So fresh ! Amazing how quickly y'all pushed that. Thanks so much.
🎉✨