RuntimeWarning: coroutine was never awaited — DedSec Project

What was created?

Calling an async def function creates a coroutine object. It does not execute the function body to completion. If that coroutine is discarded without awaiting or scheduling, Python may warn during garbage collection.

import asyncio

async def retrieve():
    await asyncio.sleep(0)
    return 42

# wrong = retrieve()   # not awaited; may produce a warning when discarded
result = asyncio.run(retrieve())
assert result == 42

Match the surrounding event loop

Use await retrieve() inside another async function. At a synchronous command-line entry point without a running event loop, asyncio.run can drive the coroutine. Inside Jupyter or an already running async application, do not nest asyncio.run; await from the existing loop instead.

async def combined():
    first = await retrieve()
    second = await retrieve()
    return first + second

assert asyncio.run(combined()) == 84

Background tasks require ownership

create_task schedules a coroutine on the current loop, but the caller should retain and await or otherwise supervise the task and handle exceptions. Simply making a task to silence a warning can lose work at shutdown. In an asyncio.TaskGroup (on supported Python versions), child tasks are awaited as the group exits.

Test: verify the coroutine really performs its intended side effect or returns expected data, rather than merely confirming the warning disappeared. Documentation: https://docs.python.org/3/library/asyncio-task.html

Keep task ownership explicit

An async def call creates a coroutine object; it does not run the body. Inside an async function, await fetch() waits for the result. If concurrent work is intended, task = asyncio.create_task(fetch()) schedules it, but the caller must eventually await or otherwise manage cancellation and failure. A discarded task can lose an exception even when the original warning disappears. Test one successful operation and one exception path under asyncio.run(main()); check that all tasks complete before the loop shuts down.