📰 Custom Issue

Since #5177, NetCDF loading is prompting verbose HDF5-DIAG warnings in some/all cases; here is an example.

@pp-mo and I have done some testing and isolated this to the advancement of libnetcdf from v4.8.1 to v4.9.1.

As far as we can tell this is probably innocuous, a view tentatively shared in pydata/xarray#7549. However it is going to start alarming developers and users alike, and will be a source of frustration given how verbose Iris' own warnings are as well. We've already had a case where it gets in the way of other print statements and thus makes ordinary work that much harder.

So far not sure what the next step is, but wanted to post this to forewarn everyone else.