descriptive BSF error message

[irenavankova]

Unclear BSF error message when analysis is run without purge

[xylar]

Here is a typical example:

Execution time: 0:00:00.33

Plotting 2-d maps of Barotropic Streamfunction climatologies for ANN on the antarctic_extended grid...
analysis task climatologyMapBSF_plotANN_antarctic_extended_10_to_-10000m failed during run
Traceback (most recent call last):
  File "/usr/projects/climate/vankova/miniconda3/envs/develop/lib/python3.13/site-packages/xarray/core/dataset.py", line 1206, in _construct_dataarray
    variable = self._variables[name]
               ~~~~~~~~~~~~~~~^^^^^^
KeyError: 'barotropicStreamfunctionAntarcticExtended'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/projects/climate/vankova/miniconda3/envs/develop/lib/python3.13/site-packages/xarray/core/dataset.py", line 1305, in __getitem__
    return self._construct_dataarray(key)
           ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^
  File "/usr/projects/climate/vankova/miniconda3/envs/develop/lib/python3.13/site-packages/xarray/core/dataset.py", line 1208, in _construct_dataarray
    _, name, variable = _get_virtual_variable(self._variables, name, self.sizes)
                        ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/projects/climate/vankova/miniconda3/envs/develop/lib/python3.13/site-packages/xarray/core/dataset_utils.py", line 79, in _get_virtual_variable
    raise KeyError(key)
KeyError: 'barotropicStreamfunctionAntarcticExtended'

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

Traceback (most recent call last):
  File "/usr/projects/climate/vankova/mpas-analysis/develop/mpas_analysis/shared/analysis_task.py", line 322, in run
    self.run_task()
    ~~~~~~~~~~~~~^^
  File "/usr/projects/climate/vankova/mpas-analysis/develop/mpas_analysis/shared/plot/plot_climatology_map_subtask.py", line 488, in run_task
    self._plot_projection(remappedModelClimatology,
    ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
                          remappedRefClimatology,
                          ^^^^^^^^^^^^^^^^^^^^^^^
                          componentName, componentSubdirectory)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/projects/climate/vankova/mpas-analysis/develop/mpas_analysis/shared/plot/plot_climatology_map_subtask.py", line 588, in _plot_projection
    remappedModelClimatology[self.mpasFieldName].values)
    ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/usr/projects/climate/vankova/miniconda3/envs/develop/lib/python3.13/site-packages/xarray/core/dataset.py", line 1318, in __getitem__
    raise KeyError(message) from e
KeyError: "No variable named 'barotropicStreamfunctionAntarcticExtended'. Did you mean one of ('barotropicStreamfunction',)?"

Execution time: 0:00:00.33

[xylar]

I think it will probably be easier to change the task that computes the BSF to recompute if plot regions are missing than it will be to have the generic PlotClimatologyMapSubtask produce a useful error message in this case.