Compiling error when compiling

[xexam]

tile.cpp.text+0x3e8b): undefined reference to `Combat:amageToConditionType(CombatType_t)'
weapons.o: In function `Weapon::useFist(Player*, Creature*)':
weapons.cpp.text+0x1382): undefined reference to `Combat::doCombatHealth(Creature*, Creature*, int, int, CombatParams const&)'
weapons.o: In function `Weapon::internalUseWeapon(Player*, Item*, Creature*, int) const':
weapons.cpp.text+0x2439): undefined reference to `Combat::doCombatHealth(Creature*, Creature*, int, int, CombatParams const&)'
weapons.o: In function `WeaponMelee::useWeapon(Player*, Item*, Creature*) const':
weapons.cpp.text+0x2639): undefined reference to `Combat::doCombatHealth(Creature*, Creature*, int, int, CombatParams const&)'
weapons.o: In function `Weapon::internalUseWeapon(Player*, Item*, Tile*) const':
weapons.cpp.text+0x27ed): undefined reference to `Combat:ostCombatEffects(Creature*, Position const&, CombatParams const&)'
collect2: ld returned 1 exit status
make[1]: *** [theforgottenserver] Error 1
make[1]: Leaving directory `/tmp'
make: *** [all] Error 2

where's the problem?