Properly check for a TPU device (#17802)

src/transformers/utils/import_utils.py

@@ -399,12 +399,16 @@ def is_ftfy_available():
 def is_torch_tpu_available():
     if not _torch_available:
         return False
-    # This test is probably enough, but just in case, we unpack a bit.
     if importlib.util.find_spec("torch_xla") is None:
         return False
-    if importlib.util.find_spec("torch_xla.core") is None:
+    import torch_xla.core.xla_model as xm
+
+    # We need to check if `xla_device` can be found, will raise a RuntimeError if not
+    try:
+        xm.xla_device()
+        return True
+    except RuntimeError:
         return False
-    return importlib.util.find_spec("torch_xla.core.xla_model") is not None
 
 
 def is_torchdynamo_available():