Ok, that are linker messages, but this is the build string
i586-mingw32msvc-g++ -I/usr/local/include -I/usr/include/freetype2 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_THREAD_SAFE -D_REENTRANT -c /home/alessandro/Documenti/ProgC/FLTK_Test/main.cpp -o obj/Debug/main.o
i586-mingw32msvc-g++ -L/usr/lib/i386-linux-gnu -L/usr/local/lib -L/home/alessandro/Scaricati/fltk-1.3.x-r11080/lib -L/usr/i586-mingw32msvc/lib -o bin/Debug/FLTK_Test obj/Debug/main.o /usr/local/lib/libfltk.a -lXrender -lXcursor -lXfixes -lXext -lXft -lfontconfig -lXinerama -lpthread -ldl -lm -lX11 /usr/lib/i386-linux-gnu/libXrender.a
obj/Debug/main.o:main.cpp:(.text+0x7d): undefined reference to `Fl_Window::Fl_Window(int, int, char const*)'
obj/Debug/main.o:main.cpp:(.text+0xbf): undefined reference to `Fl_Box::Fl_Box(int, int, int, int, char const*)'
obj/Debug/main.o:main.cpp:(.text+0x125): undefined reference to `Fl_Group::end()'
obj/Debug/main.o:main.cpp:(.text+0x13e): undefined reference to `Fl_Window::show(int, char**)'
obj/Debug/main.o:main.cpp:(.text+0x146): undefined reference to `Fl::run()'
collect2: ld returned 1 exit status
Process terminated with status 1 (0 minute(s), 0 second(s))
5 error(s), 0 warning(s) (0 minute(s), 0 second(s))
the library fltk.a in /usr/local/lib is already present in the build string but I still have errors.
Isn't it an error due to the fact that the #include file are not found?
This is the working build string used by the gnu gcc compiler:
g++ -I/usr/local/include -I/usr/include/freetype2 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_THREAD_SAFE -D_REENTRANT -g -c /home/alessandro/Documenti/ProgC/Inserimento_ordine_client/main.cpp -o obj/Debug/main.o
g++ -o bin/Debug/Inserimento_ordine_client obj/Debug/main.o /usr/local/lib/libfltk.a -lXrender -lXcursor -lXfixes -lXext -lXft -lfontconfig -lXinerama -lpthread -ldl -lm -lX11
it is neater and less messed up.
I am not able to manually edit them. I've tryed to add the library path in every project build option's linker field but nothing happpened.