/usr/include/libpng14/pngconf.h:386:12: error: '__pngconf' does not name a type
/usr/include/libpng14/pngconf.h:387:12: error: '__dont__' does not name a type
make[2]: *** [Thumbview.o] Error 1
make[2]: Leaving directory `/usr/ports/romster/nitrogen/work/src/nitrogen-1.3/src'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/ports/romster/nitrogen/work/src/nitrogen-1.3'
make: *** [all] Error 2