Yes I know about the errno. There would be two ways to resolve this:

One way would be by introducing a new exception class which would be nice because it's almost impossible to reliably check the allowed filename length (except for trial and error) and I have quite a few functions where I would want the error to propagate further as long as it's not an ENAMETOOLONG.

The other way would be by introducing a new syntax feature ("except OSError as e if e.errno == errno.ENAMETOOLONG:") but I don't think that that approach is reasonable.