Tests fail with the iOS simulator

The unit tests fail when being run on the iOS simulator. I think we already had this conversation and it might be related to the fact that the iOS simulator cannot spawn concurrent tasks because of the numbers of core.

@phausler As you are planning a v1.0 soon, I was wondering if we should make sure the tests are OK (if this is even possible) on every platform ?

Start by running the unit tests on the iOS simulator and compare the failure with a non-simulator platform. Investigate whether simulator core limits or concurrent task behavior explains the failure. Done means the unit tests run successfully on the iOS simulator and the supported platforms are documented or verified.

Written by the indexing model from the issue text.