I've got libsuitesparse-dev installed.
The results of my build are:
rob@virtual:~/gimp-build-git/plugin-dev/colorize-gimp$ make
gcc -g -Wall -O3 `gimptool-2.0 --cflags` -I/usr/include/suitesparse -I/usr/include/umfpack -c -o colorize.o colorize.c
colorize.c: In function ‘colorize’:
colorize.c:104: warning: ‘inI’ may be used uninitialized in this function
colorize.c:104: warning: ‘inQ’ may be used uninitialized in this function
colorize.c:119: warning: ‘sel_row’ may be used uninitialized in this function
gcc -g -Wall -O3 `gimptool-2.0 --cflags` -I/usr/include/suitesparse -I/usr/include/umfpack -c -o colorize-plugin.o colorize-plugin.c
gcc -g -Wall -O3 `gimptool-2.0 --cflags` -I/usr/include/suitesparse -I/usr/include/umfpack -o colorize colorize.o colorize-plugin.o `gimptool-2.0 --libs` -lumfpack -lamd -lcholmod -lm
rob@virtual:~/gimp-build-git/plugin-dev/colorize-gimp$ make install
gimptool-2.0 --install-bin colorize
cp colorize /home/rob/.gimp-2.7/plug-ins
My prefix and all other env vars are set up the same way I compile.
...update...
Running gimp from the console gives me:
/home/rob/.gimp-2.7/plug-ins/colorize: error while loading shared libraries: libgimpui-2.0.so.0: cannot open shared object file: No such file or directory
but I see it is there in /home/rob/gimp-from-git/lib/libgimpui-2.0.so.0

-Rob A>