netcdf-c: NetCDF unable to read some HDF5 enums

h5py stores boolean data using an HDF5 enum: http://docs.h5py.org/en/latest/faq.html

The attached file is a such an example: test.nc.zip

However, the netCDF-C library doesn’t report these variables at all:

$ ncdump test.nc
netcdf test {
}

This is somewhat unfortunate.

Here’s the output of h5dump on the file, along with a file created via netCDF4:

$ h5dump test.nc  $ made with h5py
HDF5 "test.nc" {
GROUP "/" {
   DATASET "foo" {
      DATATYPE  H5T_ENUM {
         H5T_STD_I8LE;
         "FALSE"            0;
         "TRUE"             1;
      }
      DATASPACE  SCALAR
      DATA {
      (0): TRUE
      }
   }
}
}
$ h5dump test2.nc  # made with netCDF4-python
HDF5 "test2.nc" {
GROUP "/" {
   DATATYPE "boolean" H5T_ENUM {
      H5T_STD_I8LE;
      "FALSE"            0;
      "TRUE"             1;
   };
   DATASET "foo" {
      DATATYPE  H5T_ENUM {
         H5T_STD_I8LE;
         "FALSE"            0;
         "TRUE"             1;
      }
      DATASPACE  SCALAR
      DATA {
      (0): TRUE
      }
   }
}
}

Scripts to produce these files:

import h5py
import numpy as np

with h5py.File('test.nc') as f:
    f.create_dataset('foo', data=np.array(True))

import netCDF4
import numpy as np
with netCDF4.Dataset('test2.nc', 'w') as ds:
    dt = ds.createEnumType('i1', 'boolean', {'FALSE': 0, 'TRUE': 1})
    v = ds.createVariable('foo', dt, ())
    v[:] = True

ncdump reports “netcdf library version 4.4.0”