Well crap, I'm not testing this but I guess I better. ;-)

Is this the cmake or autotools build? Or both?

It's both, the tests are failing due to undefined references to:

• nc_get_chunk_cache_ints
• nc_get_var_chunk_cache_ints
• nc_inq_var_chunking_ints
• nc_set_var_chunk_cache_ints
• nc_def_var_chunking_ints
• nc_set_chunk_cache_ints

Still trying to nail down where/why this is happening; I'll also get to the C PR ASAP, but need to get a 4.7.2 release out to fix this; there are a number of packages which apparently instruct their users to compile netCDF_C without netCDF4 support, and we're fielding a lot of support requests due to this issue.

configure.ac was using nc_def_opaque to determine if libnetcdf.so was built with netCDF-4 support. This is now true even if netCDF-4 support isn't actually active. As a result, USE_NETCDF4 was flagged as TRUE even when it should haven't been. Doing some digging now and will follow up.