Performing C++ SOURCE FILE Test CMAKE_HAVE_LIBC_PTHREAD failed with the following output:
Change Dir: /home/buildroot/autobuild/run/instance-2/output-1/build/zxing-cpp-1.4.0/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make -f Makefile cmTC_5fb7b/fast && make[1]: Entering directory '/home/buildroot/autobuild/run/instance-2/output-1/build/zxing-cpp-1.4.0/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make  -f CMakeFiles/cmTC_5fb7b.dir/build.make CMakeFiles/cmTC_5fb7b.dir/build
make[2]: Entering directory '/home/buildroot/autobuild/run/instance-2/output-1/build/zxing-cpp-1.4.0/buildroot-build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_5fb7b.dir/src.cxx.o
/home/buildroot/autobuild/run/instance-2/output-1/host/bin/aarch64_be-linux-gnu-g++ --sysroot=/home/buildroot/autobuild/run/instance-2/output-1/host/aarch64_be-buildroot-linux-gnu/sysroot -DCMAKE_HAVE_LIBC_PTHREAD  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -O2 -g0 -D_FORTIFY_SOURCE=1   -DNDEBUG -std=c++1z -o CMakeFiles/cmTC_5fb7b.dir/src.cxx.o -c /home/buildroot/autobuild/run/instance-2/output-1/build/zxing-cpp-1.4.0/buildroot-build/CMakeFiles/CMakeTmp/src.cxx
Linking CXX executable cmTC_5fb7b
/home/buildroot/autobuild/run/instance-2/output-1/host/bin/cmake -E cmake_link_script CMakeFiles/cmTC_5fb7b.dir/link.txt --verbose=1
/home/buildroot/autobuild/run/instance-2/output-1/host/bin/aarch64_be-linux-gnu-g++ --sysroot=/home/buildroot/autobuild/run/instance-2/output-1/host/aarch64_be-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -O2 -g0 -D_FORTIFY_SOURCE=1   -DNDEBUG CMakeFiles/cmTC_5fb7b.dir/src.cxx.o -o cmTC_5fb7b 
CMakeFiles/cmTC_5fb7b.dir/src.cxx.o: In function `main':
src.cxx:(.text.startup+0x30): undefined reference to `pthread_create'
src.cxx:(.text.startup+0x38): undefined reference to `pthread_detach'
src.cxx:(.text.startup+0x40): undefined reference to `pthread_cancel'
src.cxx:(.text.startup+0x4c): undefined reference to `pthread_join'
src.cxx:(.text.startup+0x5c): undefined reference to `pthread_atfork'
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_5fb7b.dir/build.make:98: recipe for target 'cmTC_5fb7b' failed
make[2]: *** [cmTC_5fb7b] Error 1
make[2]: Leaving directory '/home/buildroot/autobuild/run/instance-2/output-1/build/zxing-cpp-1.4.0/buildroot-build/CMakeFiles/CMakeTmp'
Makefile:127: recipe for target 'cmTC_5fb7b/fast' failed
make[1]: *** [cmTC_5fb7b/fast] Error 2
make[1]: Leaving directory '/home/buildroot/autobuild/run/instance-2/output-1/build/zxing-cpp-1.4.0/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
#include <pthread.h>

static void* test_func(void* data)
{
  return data;
}

int main(void)
{
  pthread_t thread;
  pthread_create(&thread, NULL, test_func, NULL);
  pthread_detach(thread);
  pthread_cancel(thread);
  pthread_join(thread, NULL);
  pthread_atfork(NULL, NULL, NULL);
  pthread_exit(NULL);

  return 0;
}