https://fedoraproject.org/wiki/Packaging:No_Bundled_Libraries https://fedoraproject.org/wiki/Packaging:Treatment_Of_Bundled_Libraries kolf appears to bundle Box2D which is available as a separate package in Fedora. See also external/README in the kolf source tree.
Upstream Box2D uses single-precision floats throughout, Kolf needs it to use qreal instead, which is (in Qt 4) double everywhere except on ARM, where it is float. (In Qt 5, it will be double everywhere by default.)
mark FutureFeature to avoid any chances of this getting autoclosed
it seems ti be fixed in current release