Another list already started

Can somebody explain to me what this exception from torch/csrc/jit/interpreter.cpp:548 means? I get it on calling model->forward(inputs) for the first time from a class in the same manner that I previously used it in a simple main() function.

So I’m guessing it can be caused by something being initialised wrongly or similar. I’ve confirmed that the forward() function is only getting called once before it crashes, and that inputs is defined in exactly the same way as in the tutorial.

Is it relevant that it’s coming from the bool overload of ListInsert but I’m expecting floats?

(I’m doing this from C++)