Adding limited support for unstructured grids about xmip HOT 9 OPEN

/srv/conda/envs/notebook/lib/python3.8/site-packages/xarray/coding/times.py:517: SerializationWarning: Unable to decode time axis into full numpy.datetime64 objects, continuing using cftime.datetime objects instead, reason: dates out of range
  dtype = _decode_cf_datetime_dtype(data, units, calendar, self.use_cftime)
/srv/conda/envs/notebook/lib/python3.8/site-packages/numpy/core/_asarray.py:102: SerializationWarning: Unable to decode time axis into full numpy.datetime64 objects, continuing using cftime.datetime objects instead, reason: dates out of range
  return array(a, dtype, copy=False, order=order)
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
/srv/conda/envs/notebook/lib/python3.8/site-packages/intake_esm/merge_util.py in _open_asset(path, data_format, zarr_kwargs, cdf_kwargs, preprocess, varname, requested_variables)
    314         try:
--> 315             ds = preprocess(ds)
    316         except Exception as exc:

/srv/conda/envs/notebook/lib/python3.8/site-packages/cmip6_preprocessing/preprocessing.py in combined_preprocessing(ds)
    450     # rename the `bounds` according to their style (bound or vertex)
--> 451     ds = parse_lon_lat_bounds(ds)
    452     # sort verticies in a consistent manner

/srv/conda/envs/notebook/lib/python3.8/site-packages/cmip6_preprocessing/preprocessing.py in parse_lon_lat_bounds(ds)
    282         if "x" not in ds.lat_bounds.dims:
--> 283             ds.coords["lat_bounds"] = ds.coords["lat_bounds"] * xr.ones_like(ds.x)
    284 

/srv/conda/envs/notebook/lib/python3.8/site-packages/xarray/core/common.py in __getattr__(self, name)
    238                     return source[name]
--> 239         raise AttributeError(
    240             "{!r} object has no attribute {!r}".format(type(self).__name__, name)

AttributeError: 'Dataset' object has no attribute 'x'

The above exception was the direct cause of the following exception:

RuntimeError                              Traceback (most recent call last)
<ipython-input-14-4486757f4be9> in <module>
      2 
      3 cat = col.search(source_id='AWI-ESM-1-1-LR', variable_id=['thetao'], grid_label='gn')
----> 4 ddict_awi = cat.to_dataset_dict(aggregate=False, preprocess=combined_preprocessing)

/srv/conda/envs/notebook/lib/python3.8/site-packages/intake_esm/core.py in to_dataset_dict(self, zarr_kwargs, cdf_kwargs, preprocess, storage_options, progressbar, aggregate)
    928             ]
    929             for i, task in enumerate(concurrent.futures.as_completed(future_tasks)):
--> 930                 key, ds = task.result()
    931                 self._datasets[key] = ds
    932                 if self.progressbar:

/srv/conda/envs/notebook/lib/python3.8/concurrent/futures/_base.py in result(self, timeout)
    430                 raise CancelledError()
    431             elif self._state == FINISHED:
--> 432                 return self.__get_result()
    433 
    434             self._condition.wait(timeout)

/srv/conda/envs/notebook/lib/python3.8/concurrent/futures/_base.py in __get_result(self)
    386     def __get_result(self):
    387         if self._exception:
--> 388             raise self._exception
    389         else:
    390             return self._result

/srv/conda/envs/notebook/lib/python3.8/concurrent/futures/thread.py in run(self)
     55 
     56         try:
---> 57             result = self.fn(*self.args, **self.kwargs)
     58         except BaseException as exc:
     59             self.future.set_exception(exc)

/srv/conda/envs/notebook/lib/python3.8/site-packages/intake_esm/core.py in _load_source(key, source)
    914 
    915         def _load_source(key, source):
--> 916             return key, source.to_dask()
    917 
    918         sources = {key: source(**source_kwargs) for key, source in self.items()}

/srv/conda/envs/notebook/lib/python3.8/site-packages/intake_esm/source.py in to_dask(self)
     87     def to_dask(self):
     88         """Return xarray object (which will have chunks)"""
---> 89         self._load_metadata()
     90         return self._ds
     91 

/srv/conda/envs/notebook/lib/python3.8/site-packages/intake/source/base.py in _load_metadata(self)
    234         """load metadata only if needed"""
    235         if self._schema is None:
--> 236             self._schema = self._get_schema()
    237             self.dtype = self._schema.dtype
    238             self.shape = self._schema.shape

/srv/conda/envs/notebook/lib/python3.8/site-packages/intake_esm/source.py in _get_schema(self)
     55 
     56         if self._ds is None:
---> 57             self._open_dataset()
     58 
     59             metadata = {

/srv/conda/envs/notebook/lib/python3.8/site-packages/intake_esm/source.py in _open_dataset(self)
     73     def _open_dataset(self):
     74         mapper = _path_to_mapper(self.row[self.path_column], self.storage_options, self.data_format)
---> 75         ds = _open_asset(
     76             mapper,
     77             data_format=self.data_format,

/srv/conda/envs/notebook/lib/python3.8/site-packages/intake_esm/merge_util.py in _open_asset(path, data_format, zarr_kwargs, cdf_kwargs, preprocess, varname, requested_variables)
    315             ds = preprocess(ds)
    316         except Exception as exc:
--> 317             raise RuntimeError(
    318                 f'Failed to apply pre-processing function: {preprocess.__name__}'
    319             ) from exc

RuntimeError: Failed to apply pre-processing function: combined_preprocessing