fix(outputs): Cast to sequence if num_outputs=1

Author: sebimarkgraf

onnxscript/function_libs/torch_lib/ops/core.py

@@ -8957,7 +8957,11 @@ def aten_unbind(self: TTensor, dim: int = 0) -> Sequence[TTensor]:
     if isinstance(self.shape[dim], int) and not version_utils.torch_older_than("2.7"):
         # We can create a definitive split op if the input shape is static
         # Only torch>=2.7 supports correctly generating the correct number of outputs for Split
-        outputs = op.Split(self, axis=dim, num_outputs=self.shape[dim])
+        num_outputs = self.shape[dim]
+        outputs = op.Split(self, axis=dim, num_outputs=num_outputs)
+        if num_outputs == 1:
+            outputs = [outputs]
+
         return [op.Squeeze(out, [dim]) for out in outputs]
 
     return op.SplitToSequence(self, axis=dim, keepdims=False)