On my system the ImageMagick port does not build.  This is kind of 
mysterious, as it used to build.  It could be that I upgraded XFree86-4,
or that I upgraded FreeBSD itself.  Nevertheless I seem to have found a
cure that works at least for me.

Fix: 

Removing files/patch-mi seems to fix the problem.  This patch removes
lines 
#include <sys/ipc.h>
#include <sys/shm.h>
but I don't see how calls to shmat or references to IPC_PRIVATE or such like
can possibly work without these files being included.
How-To-Repeat: 
cd /usr/ports/graphics/ImageMagick
make install clean

Eventually you get

source='xwindow.c' object='xwindow.lo' libtool=yes \
depfile='.deps/xwindow.Plo' tmpdepfile='.deps/xwindow.TPlo' \
depmode=gcc /bin/sh ../depcomp \
/bin/sh ../libtool --silent --mode=compile cc -DHAVE_CONFIG_H -I../ -I. -I. -I. 
-I.. -I../ltdl  -I/usr/local/include/freetype2 -I/usr/local/include -I/usr/X11R6
/include -I/X11 -I/usr/local/include/libxml2  -O -pipe -Wall -c -o xwindow.lo `t
est -f 'xwindow.c' || echo './'`xwindow.c
xwindow.c: In function `XInitializeWindows':
xwindow.c:4730: warning: int format, time_t arg (arg 3)
xwindow.c:4755: warning: int format, time_t arg (arg 3)
xwindow.c:4806: warning: int format, time_t arg (arg 3)
xwindow.c: In function `XMakeImage':
xwindow.c:5062: warning: implicit declaration of function `shmget'
xwindow.c:5062: `IPC_PRIVATE' undeclared (first use in this function)
xwindow.c:5062: (Each undeclared identifier is reported only once
xwindow.c:5062: for each function it appears in.)
xwindow.c:5063: `IPC_CREAT' undeclared (first use in this function)
xwindow.c:5067: warning: implicit declaration of function `shmat'
xwindow.c:5085: warning: implicit declaration of function `shmdt'
xwindow.c:5086: warning: implicit declaration of function `shmctl'
xwindow.c:5086: `IPC_RMID' undeclared (first use in this function)
xwindow.c:5116: warning: int format, time_t arg (arg 3)
xwindow.c:5178: warning: int format, time_t arg (arg 3)
xwindow.c: In function `XMakePixmap':
xwindow.c:6860: warning: int format, time_t arg (arg 3)
xwindow.c: In function `XMakeStandardColormap':
xwindow.c:7040: warning: int format, time_t arg (arg 3)
xwindow.c:7478: warning: int format, time_t arg (arg 3)
xwindow.c: In function `XSignalHandler':
xwindow.c:8355: `IPC_RMID' undeclared (first use in this function)
gmake[2]: *** [xwindow.lo] Error 1
gmake[2]: Leaving directory `/usr/ports-current/graphics/ImageMagick/work/ImageM
agick-5.4.8/magick'
gmake[1]: *** [all] Error 2
gmake[1]: Leaving directory `/usr/ports-current/graphics/ImageMagick/work/ImageM
agick-5.4.8/magick'
gmake: *** [all-recursive] Error 1
*** Error code 2

Stop in /usr/ports-current/graphics/ImageMagick.