This is my Makefile to compile the project with GTKmm.
Fill the 6th line with the names of all your .cc files (like in the first Makefile)
There is no more "make depend", you can directly use "make".
Use "make clean" to clean the .o files and the executable.
I added a "make debug" where "-D NDEBUG" is set in the CXXFLAGS for fast debugging purposes (like in the page 12 of the pdf "Préprocesseur" on topic 3). If you don't need just don't use it.
I hope it works for you.