I don't think the package is damaged (after all I've tried the packages from both stable and testing).

As I need GD.pm only because it is a dependency for some other software and I was not really sure that it would be even needed for my use-case I did a "make install" to see what would happen - and it seems to work. I can run all the demos, no errors.

For whatever reason the problem I have only seems to affect the "make test".

Weird.