Building Ghostscript from source on FreeBSD

[Brent Bloxam]

I'm having trouble building Ghostscript 8.70 from source on FreeBSD 7.0. 
I cannot use the version in the ports tree for various reasons. I've 
looked at the .mak patches in ./files/ for the ports tree however to try 
to suss out any differences but they elude me.

My configure line:
./configure --prefix=/usr/local/imagemagick-6.5.6 --disable-cups 
--disable-gtk --disable-cairo --disable-fontconfig --without-libpaper 
--without-pdftoraster --without-ijs --without-jbig2dec --without-jasper 
--without-omni --without-x --with-drivers=BMP,FAX,JPEG,PNG,PS,TIFF

The error I receive building:

gcc -Wall -Wstrict-prototypes -Wundef -Wmissing-declarations 
-Wmissing-prototypes -Wwrite-strings -Wno-strict-aliasing 
-Wdeclaration-after-statement -fno-builtin -fno-common -DHAVE_STDINT_H 
-DGX_COLOR_INDEX_TYPE="unsigned long long" -I./base -o ./obj/genconf 
./base/genconf.c
gcc: ./base/genconf.c: No such file or directory
gcc: No input files specified

./base/genconf.c exists. Executing the gcc command on its own is 
successful, yet the build can't continue even with ./obj/genconf 
existing. `make -d A` reaches the failure with:

Examining ./base/stdpn.h...modified 18:23:38 Jun 05, 2007...up-to-date.
Examining ./obj/genconf...non-existent...modified before source 
(/home/build/ghostscript-8.70/./base/genconf.c)...out-of-date.
./obj/genconf:> = /home/build/ghostscript-8.70/./base/genconf.c
./obj/genconf:? = /home/build/ghostscript-8.70/./base/genconf.c
./obj/genconf:> = /home/build/ghostscript-8.70/./base/genconf.c 
/home/build/ghostscript-8.70/./base/stdpre.h
./obj/genconf:? = /home/build/ghostscript-8.70/./base/genconf.c 
/home/build/ghostscript-8.70/./base/stdpre.h
./obj/genconf:> = /home/build/ghostscript-8.70/./base/genconf.c 
/home/build/ghostscript-8.70/./base/stdpre.h 
/home/build/ghostscript-8.70/./base/stdpn.h
./obj/genconf:? = /home/build/ghostscript-8.70/./base/genconf.c 
/home/build/ghostscript-8.70/./base/stdpre.h 
/home/build/ghostscript-8.70/./base/stdpn.h
cc -Wall -Wstrict-prototypes -Wundef -Wmissing-declarations 
-Wmissing-prototypes -Wwrite-strings -Wno-strict-aliasing 
-Wdeclaration-after-statement -fno-builtin -fno-common -DHAVE_STDINT_H 
-DGX_COLOR_INDEX_TYPE="unsigned long long" -I./base -o ./obj/genconf 
./base/genconf.c
cc: ./base/genconf.c: No such file or directory
cc: No input files specified

Why is it that it believes ./obj/genconf is nonexistent, and then 
proceeds to fail while it has no problems with anything else up to that 
point?