In file included from rrd_tool.h:145,
                 from rrd_graph.c:8:
/usr/local/include/gd.h:335: warning: declaration of 'y1' shadows a global declaration
/usr/include/math.h:253: warning: shadowed declaration is here
/usr/local/include/gd.h:339: warning: declaration of 'y1' shadows a global declaration
/usr/include/math.h:253: warning: shadowed declaration is here
/usr/local/include/gd.h:343: warning: declaration of 'y1' shadows a global declaration
/usr/include/math.h:253: warning: shadowed declaration is here
/usr/local/include/gd.h:346: warning: declaration of 'y1' shadows a global declaration
/usr/include/math.h:253: warning: shadowed declaration is here
/usr/local/include/gd.h:348: warning: declaration of 'y1' shadows a global declaration
/usr/include/math.h:253: warning: shadowed declaration is here
 cc -DHAVE_CONFIG_H -I. -I. -I.. -I.. -I/usr/local/include -I/usr/include -DFREEBSD -I/usr/local/include -I/usr/local/include -I/usr/local/include -I/usr/local/include -I/usr/local/include -I/usr/include -I/usr/include -g -O2 -fno-strict-aliasing -pipe -I/usr/local/include -g -Wshadow -Wpointer-arith -Wmissing-prototypes -Wmissing-declarations -Wnested-externs -fPIC -DPIC -MT rrd_graph.lo -MD -MP -MF .deps/rrd_graph.Tpo -c rrd_graph.c -o rrd_graph.o >/dev/null 2>&1
gmake[3]: *** [rrd_graph.lo] Error 1
gmake[3]: Leaving directory `/usr/ports/net/ntop/work/ntop-3.2/myrrd'
gmake[2]: *** [all-recursive] Error 1
gmake[2]: Leaving directory `/usr/ports/net/ntop/work/ntop-3.2/myrrd'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/usr/ports/net/ntop/work/ntop-3.2'
gmake: *** [all] Error 2
*** Error code 2

Stop in /usr/ports/net/ntop.