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Float enum query parameter fails to validate but works in plain pydantic

See original GitHub issue

Example

from enum import Enum

from fastapi import FastAPI
from pydantic import BaseModel


app = FastAPI()


class Number(float, Enum):
    ten = 10.0
    twelve = 12.0


class MyModel(BaseModel):
    num: Number


MyModel(num=10.0)  # <- This works!


@app.get("/")
async def root(num: Number):
    return {"message": f"Hello {num}"}

$ uvicorn test:app --reload
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [176218] using statreload
INFO:     Started server process [176220]
INFO:     Waiting for application startup.
INFO:     Application startup complete.

$ curl -s http://localhost:8000?num=10.0
{"detail":[{"loc":["query","num"],"msg":"value is not a valid enumeration member; permitted: 10.0, 12.0","type":"type_error.enum","ctx":{"enum_values":[10.0,12.0]}}]}

Description

Open the browser and call the endpoint /?num=10.0.
It returns a JSON with {"detail":[{"loc":["query","num"],"msg":"value is not a valid enumeration member; permitted: 10.0, 12.0","type":"type_error.enum","ctx":{"enum_values":[10.0,12.0]}}]}.
But I expected it to return {"message": "Hello 10.0"}.

Note how MyModel(num=10.0) in the example above does not throw a ValidationError, so pydantic seems to validate this fine - it is only when calling the / FastAPI endpoint with 10.0 passed for the num: Number parameter that a validation error is returned.