Coregistration failure with some Aerosol product types

[forman]

Expected behavior

Coregister Aerosol and Cloud CCI products.

Actual behavior

It seems the root cause is that Aerosol CCI products don't have a correct time encoding in Cate (this is another issue, #771). However, users should be notified in a human-readable way (raise ValidationError('Data type mismatch')). Instead they see the following:

Job: Executing operation "coregister"
Message: Failed at nopython (nopython frontend)
�[1m�[1mFailed at nopython (nopython frontend)
�[1m�[1mCannot unify array(int32, 2d, C) and array(float64, 2d, C) for 'out', defined at D:\Projects\cate\cate\ops\resampling.py (341)
�[1m
File "D:\Projects\cate\cate\ops\resampling.py", line 341:�[0m
�[1mdef _downsample_2d(src, mask, use_mask, method, fill_value, mode_rank, out):
�[1m    src_w = src.shape[-1]
�[0m    �[1m^�[0m�[0m
�[0m
�[0m�[1m[1] During: typing of assignment at D:\Projects\cate\cate\ops\resampling.py (532)�[0m
�[1m
File "D:\Projects\cate\cate\ops\resampling.py", line 532:�[0m
�[1mdef _downsample_2d(src, mask, use_mask, method, fill_value, mode_rank, out):
    <source elided>
        if method == DS_STD:
�[1m            out = np.sqrt(out)
�[0m            �[1m^�[0m�[0m

�[0m�[1m[1] During: resolving callee type: type(CPUDispatcher(<function _downsample_2d at 0x00000161C5147048>))�[0m
�[0m�[1m[2] During: typing of call at D:\Projects\cate\cate\ops\resampling.py (220)
�[0m
�[1m
File "D:\Projects\cate\cate\ops\resampling.py", line 220:�[0m
�[1mdef _resample_2d(src, mask, use_mask, ds_method, us_method, fill_value, mode_rank, out):
    <source elided>
    if out_w < src_w and out_h < src_h:
�[1m        return _downsample_2d(src, mask, use_mask, ds_method, fill_value, mode_rank, out)
�[0m        �[1m^�[0m�[0m

This is not usually a problem with Numba itself but instead often caused by
the use of unsupported features or an issue in resolving types.

To see Python/NumPy features supported by the latest release of Numba visit:
http://numba.pydata.org/numba-doc/dev/reference/pysupported.html
and
http://numba.pydata.org/numba-doc/dev/reference/numpysupported.html

For more information about typing errors and how to debug them visit:
http://numba.pydata.org/numba-doc/latest/user/troubleshoot.html#my-code-doesn-t-compile

If you think your code should work with Numba, please report the error message
and traceback, along with a minimal reproducer at:
https://github.com/numba/numba/issues/new

Code: -32003
Method: set_workspace_resource
Exception: numba.errors.TypingError

Traceback (most recent call last):
  File "D:\Projects\cate\cate\util\web\jsonrpchandler.py", line 209, in send_service_method_result
    result = future.result()
  File "D:\Miniconda3\envs\cate-env\lib\concurrent\futures\_base.py", line 425, in result
    return self.__get_result()
  File "D:\Miniconda3\envs\cate-env\lib\concurrent\futures\_base.py", line 384, in __get_result
    raise self._exception
  File "D:\Miniconda3\envs\cate-env\lib\concurrent\futures\thread.py", line 56, in run
    result = self.fn(*self.args, **self.kwargs)
  File "D:\Projects\cate\cate\util\web\jsonrpchandler.py", line 306, in call_service_method
    result = method(*method_params, monitor=monitor)
  File "D:\Projects\cate\cate\webapi\websocket.py", line 292, in set_workspace_resource
    monitor=monitor)
  File "D:\Projects\cate\cate\core\wsmanag.py", line 320, in set_workspace_resource
    workspace.execute_workflow(res_name=res_name, monitor=monitor)
  File "D:\Projects\cate\cate\core\workspace.py", line 662, in execute_workflow
    self.workflow.invoke_steps(steps, context=self._new_context(), monitor=monitor)
  File "D:\Projects\cate\cate\core\workflow.py", line 632, in invoke_steps
    step.invoke(context=context, monitor=monitor.child(work=1))
  File "D:\Projects\cate\cate\core\workflow.py", line 318, in invoke
    self._invoke_impl(_new_context(context, step=self), monitor=monitor)
  File "D:\Projects\cate\cate\core\workflow.py", line 980, in _invoke_impl
    return_value = self._op(monitor=monitor, **input_values)
  File "D:\Projects\cate\cate\core\op.py", line 216, in __call__
    return_value = self._wrapped_op(**input_values)
  File "D:\Projects\cate\cate\ops\coregistration.py", line 140, in coregister
    return _resample_dataset(ds_master, ds_slave, methods_us[method_us], methods_ds[method_ds], monitor)
  File "D:\Projects\cate\cate\ops\coregistration.py", line 314, in _resample_dataset
    retset = ds_slave.apply(_resample_array, keep_attrs=True, **kwargs)
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\xarray\core\dataset.py", line 2829, in apply
    for k, v in iteritems(self.data_vars))
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\xarray\core\dataset.py", line 2829, in <genexpr>
    for k, v in iteritems(self.data_vars))
  File "D:\Projects\cate\cate\ops\coregistration.py", line 260, in _resample_array
    temp_array = _nested_groupby_apply(array, groupby_list, _resample_slice, kwargs)
  File "D:\Projects\cate\cate\ops\coregistration.py", line 391, in _nested_groupby_apply
    return array.groupby(groupby[0], squeeze=True).apply(apply_fn, **kwargs)
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\xarray\core\groupby.py", line 516, in apply
    return self._combine(applied, shortcut=shortcut)
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\xarray\core\groupby.py", line 520, in _combine
    applied_example, applied = peek_at(applied)
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\xarray\core\utils.py", line 133, in peek_at
    peek = next(gen)
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\xarray\core\groupby.py", line 515, in <genexpr>
    for arr in grouped)
  File "D:\Projects\cate\cate\ops\coregistration.py", line 215, in _resample_slice
    us_method)
  File "D:\Projects\cate\cate\ops\resampling.py", line 100, in resample_2d
    return _mask_or_not(_resample_2d(src, mask, use_mask, ds_method, us_method, fill_value, mode_rank, out),
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\numba\dispatcher.py", line 349, in _compile_for_args
    error_rewrite(e, 'typing')
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\numba\dispatcher.py", line 316, in error_rewrite
    reraise(type(e), e, None)
  File "D:\Miniconda3\envs\cate-env\lib\site-packages\numba\six.py", line 658, in reraise
    raise value.with_traceback(tb)
numba.errors.TypingError: Failed at nopython (nopython frontend)
�[1m�[1mFailed at nopython (nopython frontend)
�[1m�[1mCannot unify array(int32, 2d, C) and array(float64, 2d, C) for 'out', defined at D:\Projects\cate\cate\ops\resampling.py (341)
�[1m
File "D:\Projects\cate\cate\ops\resampling.py", line 341:�[0m
�[1mdef _downsample_2d(src, mask, use_mask, method, fill_value, mode_rank, out):
�[1m    src_w = src.shape[-1]
�[0m    �[1m^�[0m�[0m
�[0m
�[0m�[1m[1] During: typing of assignment at D:\Projects\cate\cate\ops\resampling.py (532)�[0m
�[1m
File "D:\Projects\cate\cate\ops\resampling.py", line 532:�[0m
�[1mdef _downsample_2d(src, mask, use_mask, method, fill_value, mode_rank, out):
    <source elided>
        if method == DS_STD:
�[1m            out = np.sqrt(out)
�[0m            �[1m^�[0m�[0m

�[0m�[1m[1] During: resolving callee type: type(CPUDispatcher(<function _downsample_2d at 0x00000161C5147048>))�[0m
�[0m�[1m[2] During: typing of call at D:\Projects\cate\cate\ops\resampling.py (220)
�[0m
�[1m
File "D:\Projects\cate\cate\ops\resampling.py", line 220:�[0m
�[1mdef _resample_2d(src, mask, use_mask, ds_method, us_method, fill_value, mode_rank, out):
    <source elided>
    if out_w < src_w and out_h < src_h:
�[1m        return _downsample_2d(src, mask, use_mask, ds_method, fill_value, mode_rank, out)
�[0m        �[1m^�[0m�[0m

This is not usually a problem with Numba itself but instead often caused by
the use of unsupported features or an issue in resolving types.

To see Python/NumPy features supported by the latest release of Numba visit:
http://numba.pydata.org/numba-doc/dev/reference/pysupported.html
and
http://numba.pydata.org/numba-doc/dev/reference/numpysupported.html

For more information about typing errors and how to debug them visit:
http://numba.pydata.org/numba-doc/latest/user/troubleshoot.html#my-code-doesn-t-compile

If you think your code should work with Numba, please report the error message
and traceback, along with a minimal reproducer at:
https://github.com/numba/numba/issues/new

Steps to reproduce the problem

1. ds_cloud = open dataset "esacci.CLOUD.mon.L3C.CLD_PRODUCTS.AVHRR.multi-platform.AVHRR-PM.2-0.r1", time 2014-01-01, 2014-12-31, global, only variable cfc
2. ds_aero = open dataset "esacci.AEROSOL.mon.L3.AAI.multi-sensor.multi-platform.ms_uvai.1-5-7.r1", time 2014-01-01, 2014-12-31, global, all variables
3. coregister ds_cloud with ds_aero (lower res)

Specifications

Provide information such as the version of the project, operating system, or hardware.