Hi, I run the code:
import torch

class MyModule(torch.jit.ScriptModule):
        def __init__(self, N, M):
                super(MyModule, self).__init__()
                self.weight = torch.nn.Parameter(torch.rand(N, M))

        @torch.jit.script_method
        def forward(self, input):
                if input.sum() > 0:
                        output = self.weight.mv(input)
                else:
                        output = self.weight + input
                return output

my_script_module = MyModule(10, 20)

my_script_module.save("mymodule.pt")


However, I get an error:
Traceback (most recent call last):
  File "torchscript_annotation_convert.py", line 16, in <module>
    my_script_module = MyModule(10, 20)
  File "/home/ssm/.conda/envs/ocrcpp/lib/python3.6/site-packages/torch/jit/__init__.py", line 907, in init_then_register
    _create_methods_from_stubs(self, methods)
  File "/home/ssm/.conda/envs/ocrcpp/lib/python3.6/site-packages/torch/jit/__init__.py", line 868, in _create_methods_from_stubs
    self._create_methods(defs, rcbs, defaults)
RuntimeError: 
expected a boolean expression for condition but found Tensor, to use a tensor in a boolean expression, explicitly cast it with `bool()`:
@torch.jit.script_method
def forward(self, input):
	if input.sum() > 0:
     ~~~~~~~~~~~~~~~ <--- HERE
		output = self.weight.mv(input)
	else:
		output = self.weight + input
	return output

I guess,  input.sum() > 0 should be bool, instead of tensorbool.
Here is my environments
Package    Version          
---------- -----------------
certifi    2018.10.15       
cffi       1.11.5           
mkl-fft    1.0.6            
mkl-random 1.0.1            
numpy      1.15.4           
pip        18.1             
pycparser  2.19             
setuptools 40.6.2           
torch      1.0.0.dev20181119
wheel      0.32.3

Hope somebody help me out.