Hi I try to use torch.jit.script on my custom Concat class:
class Concat(nn.Module):
    def __init__(self, dimension=1):
        super(Concat, self).__init__()
        self.dim = dimension

    def forward(self, x):
        return torch.cat(x, dim=self.dim)

But I got the following error:

RuntimeError:
Arguments for call are not valid.
The following variants are available:
aten::cat(Tensor[] tensors, int dim=0) → (Tensor):
Expected a value of type ‘List[Tensor]’ for argument ‘tensors’ but instead found type ‘Tensor (inferred)’.
Inferred the value for argument ‘tensors’ to be of type ‘Tensor’ because it was not annotated with an explicit type.
aten::cat.names(Tensor[] tensors, str dim) → (Tensor):
Expected a value of type ‘List[Tensor]’ for argument ‘tensors’ but instead found type ‘Tensor (inferred)’.
Inferred the value for argument ‘tensors’ to be of type ‘Tensor’ because it was not annotated with an explicit type.
aten::cat.names_out(Tensor[] tensors, str dim, *, Tensor(a!) out) → (Tensor(a!)):
Expected a value of type ‘List[Tensor]’ for argument ‘tensors’ but instead found type ‘Tensor (inferred)’.
Inferred the value for argument ‘tensors’ to be of type ‘Tensor’ because it was not annotated with an explicit type.
aten::cat.out(Tensor[] tensors, int dim=0, *, Tensor(a!) out) → (Tensor(a!)):
Expected a value of type ‘List[Tensor]’ for argument ‘tensors’ but instead found type ‘Tensor (inferred)’.
Inferred the value for argument ‘tensors’ to be of type ‘Tensor’ because it was not annotated with an explicit type.

I am using PyTorch version 1.7.1+cu92, and Python 3.7.6. Is it related to this bug 2?