(py36) ~  ipython      
Python 3.6.7 |Anaconda, Inc.| (default, Oct 23 2018, 19:16:44) 
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IPython 7.2.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import torch                                                                                                                                                                     

In [2]: weights = torch.zeros(5, 6); weights[:, 3] = 1; weights = weights.cuda()                                                                                                         

In [3]: torch.multinomial(weights, num_samples=1, replacement=False)                                                                                                                     
Out[3]: 
tensor([[3],
        [3],
        [3],
        [3],
        [3]], device='cuda:0')

In [4]: torch.multinomial(weights, num_samples=2, replacement=False)                                                                                                                     
Out[4]: ---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
~/anaconda2/envs/py36/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    700                 type_pprinters=self.type_printers,
    701                 deferred_pprinters=self.deferred_printers)
--> 702             printer.pretty(obj)
    703             printer.flush()
    704             return stream.getvalue()

~/anaconda2/envs/py36/lib/python3.6/site-packages/IPython/lib/pretty.py in pretty(self, obj)
    400                         if cls is not object \
    401                                 and callable(cls.__dict__.get('__repr__')):
--> 402                             return _repr_pprint(obj, self, cycle)
    403 
    404             return _default_pprint(obj, self, cycle)

~/anaconda2/envs/py36/lib/python3.6/site-packages/IPython/lib/pretty.py in _repr_pprint(obj, p, cycle)
    695     """A pprint that just redirects to the normal repr function."""
    696     # Find newlines and replace them with p.break_()
--> 697     output = repr(obj)
    698     for idx,output_line in enumerate(output.splitlines()):
    699         if idx:

~/anaconda2/envs/py36/lib/python3.6/site-packages/torch/tensor.py in __repr__(self)
     69         # characters to replace unicode characters with.
     70         if sys.version_info > (3,):
---> 71             return torch._tensor_str._str(self)
     72         else:
     73             if hasattr(sys.stdout, 'encoding'):

~/anaconda2/envs/py36/lib/python3.6/site-packages/torch/_tensor_str.py in _str(self)
    284                 tensor_str = _tensor_str(self.to_dense(), indent)
    285             else:
--> 286                 tensor_str = _tensor_str(self, indent)
    287 
    288     if self.layout != torch.strided:

~/anaconda2/envs/py36/lib/python3.6/site-packages/torch/_tensor_str.py in _tensor_str(self, indent)
    199     if self.dtype is torch.float16:
    200         self = self.float()
--> 201     formatter = _Formatter(get_summarized_data(self) if summarize else self)
    202     return _tensor_str_with_formatter(self, indent, formatter, summarize)
    203 

~/anaconda2/envs/py36/lib/python3.6/site-packages/torch/_tensor_str.py in __init__(self, tensor)
     81         if not self.floating_dtype:
     82             for value in tensor_view:
---> 83                 value_str = '{}'.format(value)
     84                 self.max_width = max(self.max_width, len(value_str))
     85 

~/anaconda2/envs/py36/lib/python3.6/site-packages/torch/tensor.py in __format__(self, format_spec)
    384     def __format__(self, format_spec):
    385         if self.dim() == 0:
--> 386             return self.item().__format__(format_spec)
    387         return object.__format__(self, format_spec)
    388 

RuntimeError: CUDA error: device-side assert triggered