ubuntu 16.04 compile error: fatal error: device_functions.hpp: No such file or directory
```console
$ cmake .. -DCUDA_TOOLKIT_ROOT_DIR=/usr/local/cuda-9.1 -DWITH_HTTPD=OFF && make
-- The C compiler identification is GNU 5.4.0
-- The CXX compiler identification is GNU 5.4.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found UV: /usr/lib/x86_64-linux-gnu/libuv.so  
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Looking for pthread_create
-- Looking for pthread_create - not found
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE  
-- Found CUDA: /usr/local/cuda-9.1 (found suitable version "9.1", minimum required is "7.5") 
-- Found NVML: /usr/local/cuda-9.1/include  
-- Looking for syslog.h
-- Looking for syslog.h - found
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/xmrig-nvidia-2.4.2/build
[  2%] Building NVCC (Device) object CMakeFiles/xmrig-cuda.dir/src/nvidia/xmrig-cuda_generated_cuda_extra.cu.o
/tmp/xmrig-nvidia-2.4.2/src/nvidia/cuda_extra.cu:7:32: fatal error: device_functions.hpp: No such file or directory
compilation terminated.
CMake Error at xmrig-cuda_generated_cuda_extra.cu.o.cmake:207 (message):
  Error generating
  /tmp/xmrig-nvidia-2.4.2/build/CMakeFiles/xmrig-cuda.dir/src/nvidia/./xmrig-cuda_generated_cuda_extra.cu.o


make[2]: *** [CMakeFiles/xmrig-cuda.dir/src/nvidia/xmrig-cuda_generated_cuda_extra.cu.o] Error 1
CMakeFiles/xmrig-cuda.dir/build.make:70: recipe for target 'CMakeFiles/xmrig-cuda.dir/src/nvidia/xmrig-cuda_generated_cuda_extra.cu.o' failed
make[1]: *** [CMakeFiles/xmrig-cuda.dir/all] Error 2
CMakeFiles/Makefile2:104: recipe for target 'CMakeFiles/xmrig-cuda.dir/all' failed
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2
```

Could not compile. Any idea how to fix this, @xmrig?