The use case is that I would like to call async functions from heartbeat.
It is possible to change update (and I presume query) to async and thereby allow async functions to be made from them. Condvar wait not supported
However the heartbeat function appears to be sync. When I try to add async to heartbeat function definition, I get the following error:
The invocation to the wallet call forward method failed with the error: An error happened during the call: 5: Wasm module of canister sbzkb-zqaaa-aaaaa-aaaiq-cai is not valid: Wasm module has an invalid function signature. Expected return type for ‘canister_heartbeat’, got [I32]