Bug#882559: python-xarray FTBFS - GenericNetCDFDataTest.test_cross_engine_read_write_netcdf3 failed

[Rebecca N. Palmer]

Package: python3-xarray
Version: 0.9.2-1
Severity: serious
Control: tags -1 upstream

Two netcdf tests fail in current sid (see log below).

This is known upstream as https://github.com/pydata/xarray/issues/1721 , 
according to which the actual problem is that scipy has been writing 
netcdf files with invalid padding for some time ( 
https://github.com/scipy/scipy/pull/8170 ), and netcdf 4.5 rejects such 
invalid files ( https://github.com/Unidata/netcdf-c/issues/657 ).

netcdf have since reverted this change, and a patch has been posted for 
the original scipy bug, but given that neither of these are xarray's 
fault it might make most sense to temporarily disable these tests.

=================================== FAILURES 
===================================
__________ GenericNetCDFDataTest.test_cross_engine_read_write_netcdf3 
__________

self = <xarray.tests.test_backends.GenericNetCDFDataTest 
testMethod=test_cross_engine_read_write_netcdf3>

     def test_cross_engine_read_write_netcdf3(self):
         data = create_test_data()
         valid_engines = set()
         if has_netCDF4:
             valid_engines.add('netcdf4')
         if has_scipy:
             valid_engines.add('scipy')

         for write_engine in valid_engines:
             for format in ['NETCDF3_CLASSIC', 'NETCDF3_64BIT']:
                 with create_tmp_file() as tmp_file:
                     data.to_netcdf(tmp_file, format=format,
                                    engine=write_engine)
                     for read_engine in valid_engines:
                         with open_dataset(tmp_file,
 >                                         engine=read_engine) as actual:

xarray/tests/test_backends.py:977:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
_ _ _ _
xarray/backends/api.py:291: in open_dataset
     autoclose=autoclose)
xarray/backends/netCDF4_.py:210: in __init__
     self.ds = opener()
xarray/backends/netCDF4_.py:185: in _open_netcdf4_group
     ds = nc4.Dataset(filename, mode=mode, **kwargs)
netCDF4/_netCDF4.pyx:2015: in netCDF4._netCDF4.Dataset.__init__
     ???
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
_ _ _ _

 >   ???
E   OSError: [Errno -36] NetCDF: Invalid argument: 
b'/tmp/tmpmgjj7gx5/temp-88.nc'

netCDF4/_netCDF4.pyx:1636: OSError
___ 
GenericNetCDFDataTestAutocloseTrue.test_cross_engine_read_write_netcdf3 ____

self = <xarray.tests.test_backends.GenericNetCDFDataTestAutocloseTrue 
testMethod=test_cross_engine_read_write_netcdf3>

     def test_cross_engine_read_write_netcdf3(self):
         data = create_test_data()
         valid_engines = set()
         if has_netCDF4:
             valid_engines.add('netcdf4')
         if has_scipy:
             valid_engines.add('scipy')

         for write_engine in valid_engines:
             for format in ['NETCDF3_CLASSIC', 'NETCDF3_64BIT']:
                 with create_tmp_file() as tmp_file:
                     data.to_netcdf(tmp_file, format=format,
                                    engine=write_engine)
                     for read_engine in valid_engines:
                         with open_dataset(tmp_file,
 >                                         engine=read_engine) as actual:

xarray/tests/test_backends.py:977:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
_ _ _ _
xarray/backends/api.py:291: in open_dataset
     autoclose=autoclose)
xarray/backends/netCDF4_.py:210: in __init__
     self.ds = opener()
xarray/backends/netCDF4_.py:185: in _open_netcdf4_group
     ds = nc4.Dataset(filename, mode=mode, **kwargs)
netCDF4/_netCDF4.pyx:2015: in netCDF4._netCDF4.Dataset.__init__
     ???
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
_ _ _ _

 >   ???
E   OSError: [Errno -36] NetCDF: Invalid argument: 
b'/tmp/tmpfc4acgiv/temp-93.nc'

netCDF4/_netCDF4.pyx:1636: OSError

(followed by a few more failures that look like #871208 - see there)