Determining if the pthread_create exist failed with the following output:
Change Dir: /home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_5c20f/fast"
make[1]: Entering directory '/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_5c20f.dir/build.make CMakeFiles/cmTC_5c20f.dir/build
make[2]: Entering directory '/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_5c20f.dir/CheckSymbolExists.c.o
/usr/bin/gcc    -I/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/x86_64-linux-gnu/include -DNDEBUG=1 -O3  -fPIC    -o CMakeFiles/cmTC_5c20f.dir/CheckSymbolExists.c.o   -c /home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp/CheckSymbolExists.c
Linking C executable cmTC_5c20f
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_5c20f.dir/link.txt --verbose=1
/usr/bin/gcc  -I/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/x86_64-linux-gnu/include -DNDEBUG=1 -O3  -fPIC   -L/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/x86_64-linux-gnu/lib  CMakeFiles/cmTC_5c20f.dir/CheckSymbolExists.c.o  -o cmTC_5c20f -rdynamic
CMakeFiles/cmTC_5c20f.dir/CheckSymbolExists.c.o: In function `main':
CheckSymbolExists.c:(.text.startup+0x3): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_5c20f.dir/build.make:97: commands for the object 'cmTC_5c20f' failed
make[2]: *** [cmTC_5c20f] Error 1
make[2]: Leaving directory '/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp'
Makefile:126: commands for the object 'cmTC_5c20f/fast' failed
make[1]: *** [cmTC_5c20f/fast] Error 2
make[1]: Leaving directory '/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp'

File /home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <pthread.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef pthread_create
  return ((int*)(&pthread_create))[argc];
#else
  (void)argc;
  return 0;
#endif
}

Determining if the function pthread_create exists in the pthreads failed with the following output:
Change Dir: /home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_9e603/fast"
make[1]: Entering directory '/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_9e603.dir/build.make CMakeFiles/cmTC_9e603.dir/build
make[2]: Entering directory '/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_9e603.dir/CheckFunctionExists.c.o
/usr/bin/gcc    -I/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/x86_64-linux-gnu/include -DNDEBUG=1 -O3  -fPIC -DCHECK_FUNCTION_EXISTS=pthread_create   -o CMakeFiles/cmTC_9e603.dir/CheckFunctionExists.c.o   -c /usr/share/cmake-3.7/Modules/CheckFunctionExists.c
Linking C executable cmTC_9e603
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_9e603.dir/link.txt --verbose=1
/usr/bin/gcc  -I/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/x86_64-linux-gnu/include -DNDEBUG=1 -O3  -fPIC -DCHECK_FUNCTION_EXISTS=pthread_create  -L/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/x86_64-linux-gnu/lib  CMakeFiles/cmTC_9e603.dir/CheckFunctionExists.c.o  -o cmTC_9e603 -rdynamic -lpthreads
/usr/bin/ld: cannot find -lpthreads
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_9e603.dir/build.make:97: commands for the object 'cmTC_9e603' failed
make[2]: *** [cmTC_9e603] Error 1
make[2]: Leaving directory '/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp'
Makefile:126: commands for the object 'cmTC_9e603/fast' failed
make[1]: *** [cmTC_9e603/fast] Error 2
make[1]: Leaving directory '/home/szeregowy/Dokumenty/Programy/Paczki/ring-project/daemon/contrib/native/opendht/CMakeFiles/CMakeTmp'