virtual keys error when compiling for first go on Linux

++] Universal_System/Extensions/ParticleSystems/PS_particle_destroyer.cpp
[g++] Universal_System/Extensions/ParticleSystems/PS_particle_emitter.cpp
[g++] Universal_System/Extensions/ParticleSystems/PS_particle_changer.cpp
[g++] Universal_System/Extensions/ParticleSystems/PS_actions.cpp
[g++] Universal_System/Extensions/ParticleSystems/PS_particle_attractor.cpp
[g++] Universal_System/Extensions/ParticleSystems/PS_effects.cpp
[g++] Universal_System/Extensions/Timelines/timelines.cpp
[g++] Bridges/OpenGL/GLload.cpp
[g++] Bridges/xlib-OpenGL/graphics_bridge.cpp
[g++] ../../shared/rectpacker/rectpack.cpp
Linking /tmp/egm4234200667584339360.tmp
/usr/bin/ld: /home/hughie32/.enigma/.eobjs/Linux/Linux/GNU_GCC_G++/Run/Universal_System/Extensions/VirtualKeys/virtualkeys.o: in function `(anonymous namespace)::update_virtualkeys()':
virtualkeys.cpp:(.text+0x8a): undefined reference to `enigma_user::keyboard_key_press(int)'
/usr/bin/ld: virtualkeys.cpp:(.text+0x1ae): undefined reference to `enigma_user::keyboard_key_release(int)'
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:146: compile_game] Error 1
make[1]: Leaving directory '/home/hughie32/enigma-dev/ENIGMAsystem/SHELL'
make: *** [Makefile:22: Game] Error 2