elixir - `Task.async` times out on query inside `Ecto.Multi` in tests -

i'm struggling perform async operation inside 1 of steps in ecto.multi. here i'll present minimal version describe problem:

defmodule mymodule   my_function(repo \\ repo)     ecto.multi.new()     |> ecto.multi.run(:example, &perform_example(&1, repo))     |> repo.transaction()   end    def perform_example(_changes_so_far, repo)     task.async(fn -> repo.all(datamodule) end)     |> io.inspect() # 1.     |> task.await() # 2.     |> io.inspect()   end end  mymodule.my_function(repo) 

1. seems working correctly yealds task struct:

%task{owner: #pid<0.352.0>, pid: #pid<0.354.0>,       ref: #reference<0.2903625078.3861118978.56327>} 

2. unfortunately raises error:

     ** (exit #pid<0.352.0>) exited in: genserver.call(#pid<0.353.0>, {:checkout, #reference<0.2903625078.3861118978.56400>, true, 15000}, 5000)          ** (exit) time out 

strangely enough, i've tried perform same code outside multi , worked correctly... problem problem how multi works?

i've tried exercise code using related functionality , seemed working correctly. it's issue inside 1 of multi steps when executing in test environment.

ecto not support multiple processes using single transaction. not clear semantics of such setup , should happen if 1 of processes fails.