Is it possible to mount multiple Gradio apps with FastAPI? I’d like to have two endpoints: localhost:8000 and localhost:8000/debug. The /debug endpoint would ultimately be a bit more complex and log more data. I thought I’d be able to do something like this:

from fastapi import FastAPI
from functools import partial
import gradio as gr

app = FastAPI()
sub_app = FastAPI()
app.mount('/debug', sub_app)

def out(text, n):
    return text + '!'*n

def make_simple_gr_app(n):
    func = partial(out, n=n)
    with gr.Blocks() as dbg:
        textbox = gr.Textbox(max_lines=1, label='Enter text')
        submit_btn = gr.Button('Submit')
        submit_btn.click(func, inputs=textbox, outputs=textbox)
    return dbg

sub_app = gr.mount_gradio_app(sub_app, make_simple_gr_app(1), '/')
app = gr.mount_gradio_app(app, make_simple_gr_app(5), '/')

Now when I go to localhost:8000 it works, but when accessing localhost:8000/debug the logs show "GET /debug HTTP/1.1" 404 Not Found which I don’t understand since I would think the app.mount(..) would take care of that part.

What am I missing?