darknet-nnpack make failed

[wangbard]

I failed to build NNPACK-darknet through ninja. Therefore, i swtiched to cmake/make instead. Below is the cmake command i used

cmake .. -DCMAKE_C_FLAGS=-march=armv6k

However, when I try to build darknet-nnpack, strange error occures.
To note, i am working on a rasberrypi 3B. Below is the error:

/usr/bin/ld: /usr/lib/gcc/arm-linux-gnueabihf/10/../../../libpthreadpool.a(pthreads.c.o): in function pthreadpool_create': /home/pi/NNPACK/deps/pthreadpool/src/pthreads.c:258: undefined reference to pthreadpool_allocate'
/usr/bin/ld: /usr/lib/gcc/arm-linux-gnueabihf/10/../../../libpthreadpool.a(pthreads.c.o): in function pthreadpool_destroy': /home/pi/NNPACK/deps/pthreadpool/src/pthreads.c:459: undefined reference to pthreadpool_deallocate'
/usr/bin/ld: /home/pi/NNPACK/deps/pthreadpool/src/pthreads.c:459: undefined reference to pthreadpool_deallocate' /usr/bin/ld: darknet: internal symbol pthreadpool_deallocate' isn't defined
/usr/bin/ld: final link failed: bad value
collect2: error: ld returned 1 exit status

Could anyone lend a hand? I am really stressed.