h5py raising on xr.show_versions()

[max-sixty]

Any ideas why __hdf5libversion__ wouldn't be available? Shall I put a try / except around it?

In [4]: import xarray as xr

In [5]: xr.show_versions()
---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
/usr/local/lib/python3.7/site-packages/xarray/util/print_versions.py in netcdf_and_hdf5_versions()
     64     try:
---> 65         import netCDF4
     66         libhdf5_version = netCDF4.__hdf5libversion__

ModuleNotFoundError: No module named 'netCDF4'

During handling of the above exception, another exception occurred:

AttributeError                            Traceback (most recent call last)
<ipython-input-5-6f391305f2fe> in <module>
----> 1 xr.show_versions()

/usr/local/lib/python3.7/site-packages/xarray/util/print_versions.py in show_versions(file)
     78     sys_info = get_sys_info()
     79
---> 80     sys_info.extend(netcdf_and_hdf5_versions())
     81
     82     deps = [

/usr/local/lib/python3.7/site-packages/xarray/util/print_versions.py in netcdf_and_hdf5_versions()
     69         try:
     70             import h5py
---> 71             libhdf5_version = h5py.__hdf5libversion__
     72         except ImportError:
     73             pass

AttributeError: module 'h5py' has no attribute '__hdf5libversion__'

I check I'm on the latest h5py:

pip install h5py -U                                                                                                   Thu Jul 18 16:47:29 2019
Requirement already up-to-date: h5py in ./Library/Python/3.7/lib/python/site-packages (2.9.0)
Requirement already satisfied, skipping upgrade: numpy>=1.7 in /usr/local/lib/python3.7/site-packages (from h5py) (1.16.4)
Requirement already satisfied, skipping upgrade: six in ./Library/Python/3.7/lib/python/site-packages (from h5py) (1.12.0)

[shoyer]

Hmm, now I'm not sure that line ever worked. I may just copied the variable from netCDF4.

It think it should be h5py.version.hdf5_version, which has been around in h5py for quite a while, e.g.,
https://github.com/h5py/h5py/blob/2.0.0/h5py/version.py#L8
https://github.com/h5py/h5py/blob/2.9.0/h5py/version.py#L39

But yes, let's catch AttributeError, too, just in case that changes in the future.

[max-sixty]

I think it must work under some setups, since it's tested. I changed and added a broader try / except

[shoyer]

I don't think we have any CI configurations with h5py installed but not netCDF4.