I am having trouble trying to parallelize an OpenMDAO problem due to the presence of weakrefs to some object instances within the code. I am serializing the data using Dill, which does not raise any errors. However, when debugging it says that some variables have become NoneType and lost all of their information.
I am trying to optimize the problem using an external optimization library which allows for parallel processing (pygmo). I am expecting to run the same problem in multiple different processes, but instead an error is raised telling me some variables have become NoneType and no longer have attributes.