Determining if the pthread_create exist failed with the following output:
Change Dir: /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp

Run Build Command:/usr/bin/make "cmTryCompileExec976433600/fast"
/usr/bin/make -f CMakeFiles/cmTryCompileExec976433600.dir/build.make CMakeFiles/cmTryCompileExec976433600.dir/build
make[1]: Entering directory `/var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp'
/usr/bin/cmake -E cmake_progress_report /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp/CMakeFiles 1
Building C object CMakeFiles/cmTryCompileExec976433600.dir/CheckSymbolExists.c.o
/usr/lib/ccache/cc    -o CMakeFiles/cmTryCompileExec976433600.dir/CheckSymbolExists.c.o   -c /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
Linking C executable cmTryCompileExec976433600
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTryCompileExec976433600.dir/link.txt --verbose=1
/usr/lib/ccache/cc       CMakeFiles/cmTryCompileExec976433600.dir/CheckSymbolExists.c.o  -o cmTryCompileExec976433600 -rdynamic -lm 
CMakeFiles/cmTryCompileExec976433600.dir/CheckSymbolExists.c.o: In function `main':
CheckSymbolExists.c:(.text+0xa): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
make[1]: Leaving directory `/var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp'
make[1]: *** [cmTryCompileExec976433600] Error 1
make: *** [cmTryCompileExec976433600/fast] Error 2

File /var/uhubuild/work/compile/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: /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp

Run Build Command:/usr/bin/make "cmTryCompileExec1765460606/fast"
/usr/bin/make -f CMakeFiles/cmTryCompileExec1765460606.dir/build.make CMakeFiles/cmTryCompileExec1765460606.dir/build
make[1]: Entering directory `/var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp'
/usr/bin/cmake -E cmake_progress_report /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp/CMakeFiles 1
Building C object CMakeFiles/cmTryCompileExec1765460606.dir/CheckFunctionExists.c.o
/usr/lib/ccache/cc   -DCHECK_FUNCTION_EXISTS=pthread_create   -o CMakeFiles/cmTryCompileExec1765460606.dir/CheckFunctionExists.c.o   -c /usr/share/cmake-2.8/Modules/CheckFunctionExists.c
Linking C executable cmTryCompileExec1765460606
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTryCompileExec1765460606.dir/link.txt --verbose=1
/usr/lib/ccache/cc   -DCHECK_FUNCTION_EXISTS=pthread_create    CMakeFiles/cmTryCompileExec1765460606.dir/CheckFunctionExists.c.o  -o cmTryCompileExec1765460606 -rdynamic -lpthreads -lm 
/usr/bin/ld: cannot find -lpthreads
collect2: error: ld returned 1 exit status
make[1]: *** [cmTryCompileExec1765460606] Error 1
make[1]: Leaving directory `/var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp'
make: *** [cmTryCompileExec1765460606/fast] Error 2