Mine

fluid@fluid-desktop:~/src/icns2png$ make
c++ -o icns2png -O -Ilibpng-config -Izlib-1.1.4 icns2png.o iconvert.o pngwriter.o byteswap.o -Llibpng-config -Lzlib-1.1.4 libpng-config/libpng.a -lz -lm
c++: libpng-config/libpng.a: No such file or directory
make: *** [icns2png] Error 1
fluid@fluid-desktop:~/src/icns2png$ mc
fluid@fluid-desktop:~/src/icns-gimp-0.1$ make
gcc `gimptool-2.0 --cflags` -I/sw/include -c main.c -o main.o
gcc `gimptool-2.0 --cflags` -I/sw/include -c icnsload.c -o icnsload.o
icnsload.c:57:23: warning: multi-character character constant
icnsload.c:219:25: warning: multi-character character constant
icnsload.c: In function ‘icns_load’:
icnsload.c:363: error: label at end of compound statement
make: *** [icnsload.o] Error 1