Determining if the pthread_create exist failed with the following output:
Change Dir: /home/rock/kodi-build/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_4eec2/fast"
/usr/bin/make -f CMakeFiles/cmTC_4eec2.dir/build.make CMakeFiles/cmTC_4eec2.dir/build
make[1]: ingresso nella directory "/home/rock/kodi-build/CMakeFiles/CMakeTmp"
Building C object CMakeFiles/cmTC_4eec2.dir/CheckSymbolExists.c.o
/usr/bin/cc    -DPLATFORM_SETTINGS_FILE=x11.xml -Wall    -o CMakeFiles/cmTC_4eec2.dir/CheckSymbolExists.c.o   -c /home/rock/kodi-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
Linking C executable cmTC_4eec2
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_4eec2.dir/link.txt --verbose=1
/usr/bin/cc  -DPLATFORM_SETTINGS_FILE=x11.xml -Wall    -fuse-ld=gold  CMakeFiles/cmTC_4eec2.dir/CheckSymbolExists.c.o  -o cmTC_4eec2
CMakeFiles/cmTC_4eec2.dir/CheckSymbolExists.c.o:CheckSymbolExists.c:function main: error: undefined reference to 'pthread_create'
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_4eec2.dir/build.make:97: set di istruzioni per l'obiettivo "cmTC_4eec2" non riuscito
make[1]: *** [cmTC_4eec2] Errore 1
make[1]: uscita dalla directory "/home/rock/kodi-build/CMakeFiles/CMakeTmp"
Makefile:126: set di istruzioni per l'obiettivo "cmTC_4eec2/fast" non riuscito
make: *** [cmTC_4eec2/fast] Errore 2

File /home/rock/kodi-build/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/rock/kodi-build/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_abdc6/fast"
/usr/bin/make -f CMakeFiles/cmTC_abdc6.dir/build.make CMakeFiles/cmTC_abdc6.dir/build
make[1]: ingresso nella directory "/home/rock/kodi-build/CMakeFiles/CMakeTmp"
Building C object CMakeFiles/cmTC_abdc6.dir/CheckFunctionExists.c.o
/usr/bin/cc    -DPLATFORM_SETTINGS_FILE=x11.xml -Wall -DCHECK_FUNCTION_EXISTS=pthread_create   -o CMakeFiles/cmTC_abdc6.dir/CheckFunctionExists.c.o   -c /usr/share/cmake-3.7/Modules/CheckFunctionExists.c
Linking C executable cmTC_abdc6
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_abdc6.dir/link.txt --verbose=1
/usr/bin/cc  -DPLATFORM_SETTINGS_FILE=x11.xml -Wall -DCHECK_FUNCTION_EXISTS=pthread_create   -fuse-ld=gold  CMakeFiles/cmTC_abdc6.dir/CheckFunctionExists.c.o  -o cmTC_abdc6 -lpthreads
/usr/bin/ld.gold: errore: impossibile trovare -lpthreads
CMakeFiles/cmTC_abdc6.dir/CheckFunctionExists.c.o:CheckFunctionExists.c:function main: error: undefined reference to 'pthread_create'
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_abdc6.dir/build.make:97: set di istruzioni per l'obiettivo "cmTC_abdc6" non riuscito
make[1]: *** [cmTC_abdc6] Errore 1
make[1]: uscita dalla directory "/home/rock/kodi-build/CMakeFiles/CMakeTmp"
Makefile:126: set di istruzioni per l'obiettivo "cmTC_abdc6/fast" non riuscito
make: *** [cmTC_abdc6/fast] Errore 2