Error in installing

[hap662000]

ld: obj/com/interrupts.o: in function oudad::com::InterruptManager::DoHandleInterrupt(unsigned char, unsigned int)': interrupts.cpp:(.text+0xa6f): undefined reference to oudad::TaskManager::Schedule(oudad::CPUState*)'
ld: obj/kernel.o: in function kernelMain': kernel.cpp:(.text+0x3d8): undefined reference to oudad::TaskManager::TaskManager()'
ld: kernel.cpp:(.text+0x3f5): undefined reference to oudad::Task::Task(oudad::GlobalDescriptorTable*, void (*)())' ld: kernel.cpp:(.text+0x412): undefined reference to oudad::Task::Task(oudad::GlobalDescriptorTable*, void (*)())'

This error is coming while running make oudadOS.iso