python

PyTorch second backward pass without retain_graph

RuntimeError: Trying to backward through the graph a second time

Fixes

1.Use loss.backward(retain_graph=True) if you need multiple passes
2.Restructure code to avoid needing multiple backward passes
3.Detach intermediate tensors that don't need gradients in second pass

pytorchautograd

Related Errors

Asyncio event loop already running

RuntimeError: This event loop is already running

•Use nest_asyncio.apply() to allow nested event loops
•Use asyncio.run_coroutine_threadsafe() instead of asyncio.run()

Coroutine never awaited

RuntimeWarning: coroutine '.*' was never awaited

•Add 'await' before the coroutine call
•Use asyncio.create_task() to schedule the coroutine

Asyncio task was cancelled

asyncio\.CancelledError

•Handle CancelledError in try/except within the task
•Use asyncio.shield() to protect critical sections from cancellation