While working on issue 454 we noticed that the dmr file on the server is different than the local dmr file.
Currently, the hdf5 creates cached files that hold synthesized values for lat and lon. When the dmr++ is built it uses the HDF5 API to interrogate the data file, but there is no lat or lon variable in the local file and an error is thrown.
A design is needed for how to provide the synthetic variables or detect that synthetic variables are being used and look in the cache for them.
Things to consider:
libdap::BaseType has an _is_synthesized_p property_
Store the data for the synthetic variables in a separate s3 object
Include the feature in build_dmrpp or use the handler to get the data?