If you have a GNUstep program that is licensed under the terms of the
GPLv2 *only*, you should do one of the following (in no particular
order):
- change the license to "GPLv2 or later"
- change the license to GPLv3 (or later)
- change the license to something completely different that the LGPLv3
is compatible with (e.g. MIT, 3-clause BSD)
- add an exception that allows linking with the GNUstep libraries or
LGPL'ed libraries (e.g. see for example
http://www.gnu.org/licenses/gpl-faq.html#LinkingOverControlledInterface
or http://price.sourceforge.net/exception.html