Determining if the res_ndestroy exist failed with the following output:
Change Dir: /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/gmake" "cmTC_b989b/fast"
/usr/bin/gmake -f CMakeFiles/cmTC_b989b.dir/build.make CMakeFiles/cmTC_b989b.dir/build
gmake[1]: Entering directory '/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_b989b.dir/CheckSymbolExists.c.o
/usr/bin/x86_64-pc-linux-gnu-gcc    -DNDEBUG -O2 -pipe -march=native    -o CMakeFiles/cmTC_b989b.dir/CheckSymbolExists.c.o -c /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c: In function ‘main’:
/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:8:19: error: ‘res_ndestroy’ undeclared (first use in this function); did you mean ‘res_nsearch’?
   return ((int*)(&res_ndestroy))[argc];
                   ^~~~~~~~~~~~
                   res_nsearch
/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:8:19: note: each undeclared identifier is reported only once for each function it appears in
gmake[1]: *** [CMakeFiles/cmTC_b989b.dir/build.make:66: CMakeFiles/cmTC_b989b.dir/CheckSymbolExists.c.o] Error 1
gmake[1]: Leaving directory '/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp'
gmake: *** [Makefile:121: cmTC_b989b/fast] Error 2

File /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <resolv.h>

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

Determining if the sched_getcpu exist failed with the following output:
Change Dir: /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/gmake" "cmTC_4e8ff/fast"
/usr/bin/gmake -f CMakeFiles/cmTC_4e8ff.dir/build.make CMakeFiles/cmTC_4e8ff.dir/build
gmake[1]: Entering directory '/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_4e8ff.dir/CheckSymbolExists.c.o
/usr/bin/x86_64-pc-linux-gnu-gcc    -DNDEBUG -O2 -pipe -march=native    -o CMakeFiles/cmTC_4e8ff.dir/CheckSymbolExists.c.o -c /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c: In function ‘main’:
/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:8:19: error: ‘sched_getcpu’ undeclared (first use in this function); did you mean ‘sched_getparam’?
   return ((int*)(&sched_getcpu))[argc];
                   ^~~~~~~~~~~~
                   sched_getparam
/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:8:19: note: each undeclared identifier is reported only once for each function it appears in
gmake[1]: *** [CMakeFiles/cmTC_4e8ff.dir/build.make:66: CMakeFiles/cmTC_4e8ff.dir/CheckSymbolExists.c.o] Error 1
gmake[1]: Leaving directory '/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp'
gmake: *** [Makefile:121: cmTC_4e8ff/fast] Error 2

File /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <sched.h>

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

Determining if the pthread_create exist failed with the following output:
Change Dir: /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/gmake" "cmTC_14768/fast"
/usr/bin/gmake -f CMakeFiles/cmTC_14768.dir/build.make CMakeFiles/cmTC_14768.dir/build
gmake[1]: Entering directory '/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_14768.dir/CheckSymbolExists.c.o
/usr/bin/x86_64-pc-linux-gnu-gcc    -DNDEBUG -O2 -pipe -march=native    -o CMakeFiles/cmTC_14768.dir/CheckSymbolExists.c.o -c /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
Linking C executable cmTC_14768
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_14768.dir/link.txt --verbose=1
/usr/bin/x86_64-pc-linux-gnu-gcc -O2 -pipe -march=native   -Wl,-O1 -Wl,--as-needed  -rdynamic CMakeFiles/cmTC_14768.dir/CheckSymbolExists.c.o  -o cmTC_14768 
CMakeFiles/cmTC_14768.dir/CheckSymbolExists.c.o: In function `main':
CheckSymbolExists.c:(.text.startup+0x1a): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
gmake[1]: *** [CMakeFiles/cmTC_14768.dir/build.make:87: cmTC_14768] Error 1
gmake[1]: Leaving directory '/var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_build/CMakeFiles/CMakeTmp'
gmake: *** [Makefile:121: cmTC_14768/fast] Error 2

File /var/tmp/portage/dev-libs/mongo-c-driver-1.11.0/work/mongo-c-driver-1.11.0_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
}