Performing C SOURCE FILE Test C_SUPPORTS_WERROR_UNGUARDED_AVAILABILITY_NEW failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_59519/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_59519.dir/build.make CMakeFiles/cmTC_59519.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_59519.dir/src.c.o
/usr/bin/gcc   -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -DC_SUPPORTS_WERROR_UNGUARDED_AVAILABILITY_NEW   -Werror -Werror=unguarded-availability-new -o CMakeFiles/cmTC_59519.dir/src.c.o   -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.c
cc1: error: '-Werror=unguarded-availability-new': no option -Wunguarded-availability-new
make[2]: *** [CMakeFiles/cmTC_59519.dir/build.make:66: CMakeFiles/cmTC_59519.dir/src.c.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_59519/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
int main(void) { return 0; }
Performing C++ SOURCE FILE Test CXX_SUPPORTS_WERROR_UNGUARDED_AVAILABILITY_NEW failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_8b1a4/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_8b1a4.dir/build.make CMakeFiles/cmTC_8b1a4.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_8b1a4.dir/src.cxx.o
/usr/bin/g++    -O2 -I/tmp/instance-11/output-1/host/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -DCXX_SUPPORTS_WERROR_UNGUARDED_AVAILABILITY_NEW   -Werror -Werror=unguarded-availability-new -o CMakeFiles/cmTC_8b1a4.dir/src.cxx.o -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.cxx
cc1plus: error: '-Werror=unguarded-availability-new': no option -Wunguarded-availability-new
make[2]: *** [CMakeFiles/cmTC_8b1a4.dir/build.make:66: CMakeFiles/cmTC_8b1a4.dir/src.cxx.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_8b1a4/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
int main() { return 0; }
Performing C SOURCE FILE Test C_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_9e703/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_9e703.dir/build.make CMakeFiles/cmTC_9e703.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_9e703.dir/src.c.o
/usr/bin/gcc   -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -DC_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG   -Werror -Wcovered-switch-default -o CMakeFiles/cmTC_9e703.dir/src.c.o   -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.c
gcc: error: unrecognized command line option '-Wcovered-switch-default'; did you mean '-Wno-switch-default'?
make[2]: *** [CMakeFiles/cmTC_9e703.dir/build.make:66: CMakeFiles/cmTC_9e703.dir/src.c.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_9e703/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
int main(void) { return 0; }
Performing C++ SOURCE FILE Test CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_59901/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_59901.dir/build.make CMakeFiles/cmTC_59901.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_59901.dir/src.cxx.o
/usr/bin/g++    -O2 -I/tmp/instance-11/output-1/host/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -std=c++11 -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -Wimplicit-fallthrough -DCXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG   -Werror -Wcovered-switch-default -o CMakeFiles/cmTC_59901.dir/src.cxx.o -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.cxx
g++: error: unrecognized command line option '-Wcovered-switch-default'; did you mean '-Wno-switch-default'?
make[2]: *** [CMakeFiles/cmTC_59901.dir/build.make:66: CMakeFiles/cmTC_59901.dir/src.cxx.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_59901/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
int main() { return 0; }
Performing C SOURCE FILE Test C_SUPPORTS_DELETE_NON_VIRTUAL_DTOR_FLAG failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_e4e13/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_e4e13.dir/build.make CMakeFiles/cmTC_e4e13.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_e4e13.dir/src.c.o
/usr/bin/gcc   -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -DC_SUPPORTS_DELETE_NON_VIRTUAL_DTOR_FLAG   -Werror -Wdelete-non-virtual-dtor -o CMakeFiles/cmTC_e4e13.dir/src.c.o   -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.c
cc1: error: command line option '-Wdelete-non-virtual-dtor' is valid for C++/ObjC++ but not for C [-Werror]
cc1: all warnings being treated as errors
make[2]: *** [CMakeFiles/cmTC_e4e13.dir/build.make:66: CMakeFiles/cmTC_e4e13.dir/src.c.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_e4e13/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
int main(void) { return 0; }
Performing C SOURCE FILE Test C_WCOMMENT_ALLOWS_LINE_WRAP failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_13128/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_13128.dir/build.make CMakeFiles/cmTC_13128.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_13128.dir/src.c.o
/usr/bin/gcc   -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -DC_WCOMMENT_ALLOWS_LINE_WRAP  -Werror -Wcomment   -o CMakeFiles/cmTC_13128.dir/src.c.o   -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.c
/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.c:1:1: error: multi-line comment [-Werror=comment]
    1 | // \
      | ^
cc1: all warnings being treated as errors
make[2]: *** [CMakeFiles/cmTC_13128.dir/build.make:66: CMakeFiles/cmTC_13128.dir/src.c.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_13128/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
// \
//
int main() {return 0;}
Performing C SOURCE FILE Test C_SUPPORTS_STRING_CONVERSION_FLAG failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_efb56/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_efb56.dir/build.make CMakeFiles/cmTC_efb56.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_efb56.dir/src.c.o
/usr/bin/gcc   -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -Wno-comment -DC_SUPPORTS_STRING_CONVERSION_FLAG   -Werror -Wstring-conversion -o CMakeFiles/cmTC_efb56.dir/src.c.o   -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.c
gcc: error: unrecognized command line option '-Wstring-conversion'; did you mean '-Wsign-conversion'?
make[2]: *** [CMakeFiles/cmTC_efb56.dir/build.make:66: CMakeFiles/cmTC_efb56.dir/src.c.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_efb56/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
int main(void) { return 0; }
Performing C++ SOURCE FILE Test CXX_SUPPORTS_STRING_CONVERSION_FLAG failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_2e5be/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_2e5be.dir/build.make CMakeFiles/cmTC_2e5be.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_2e5be.dir/src.cxx.o
/usr/bin/g++    -O2 -I/tmp/instance-11/output-1/host/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -std=c++11 -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -Wimplicit-fallthrough -Wno-class-memaccess -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -DCXX_SUPPORTS_STRING_CONVERSION_FLAG   -Werror -Wstring-conversion -o CMakeFiles/cmTC_2e5be.dir/src.cxx.o -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.cxx
g++: error: unrecognized command line option '-Wstring-conversion'; did you mean '-Wsign-conversion'?
make[2]: *** [CMakeFiles/cmTC_2e5be.dir/build.make:66: CMakeFiles/cmTC_2e5be.dir/src.cxx.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_2e5be/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
int main() { return 0; }
Determining if the os_signpost_interval_begin exist failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_a7e92/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_a7e92.dir/build.make CMakeFiles/cmTC_a7e92.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_a7e92.dir/CheckSymbolExists.c.o
/usr/bin/gcc   -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -Wno-comment -ffunction-sections -fdata-sections    -o CMakeFiles/cmTC_a7e92.dir/CheckSymbolExists.c.o   -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:2:10: fatal error: os/signpost.h: No such file or directory
    2 | #include <os/signpost.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [CMakeFiles/cmTC_a7e92.dir/build.make:66: CMakeFiles/cmTC_a7e92.dir/CheckSymbolExists.c.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_a7e92/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


File /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <os/signpost.h>

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

Performing C++ SOURCE FILE Test CXX_SUPPORTS_NO_NESTED_ANON_TYPES_FLAG failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_ab1fe/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_ab1fe.dir/build.make CMakeFiles/cmTC_ab1fe.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_ab1fe.dir/src.cxx.o
/usr/bin/g++    -O2 -I/tmp/instance-11/output-1/host/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -std=c++11 -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -Wimplicit-fallthrough -Wno-class-memaccess -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -fno-strict-aliasing -pedantic -Wno-long-long -DCXX_SUPPORTS_NO_NESTED_ANON_TYPES_FLAG   -Werror -Wnested-anon-types -o CMakeFiles/cmTC_ab1fe.dir/src.cxx.o -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.cxx
g++: error: unrecognized command line option '-Wnested-anon-types'
make[2]: *** [CMakeFiles/cmTC_ab1fe.dir/build.make:66: CMakeFiles/cmTC_ab1fe.dir/src.cxx.o] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_ab1fe/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
int main() { return 0; }
Performing C SOURCE FILE Test CMAKE_HAVE_LIBC_PTHREAD failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_c19dd/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_c19dd.dir/build.make CMakeFiles/cmTC_c19dd.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_c19dd.dir/src.c.o
/usr/bin/gcc   -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -Wno-comment -ffunction-sections -fdata-sections -DCMAKE_HAVE_LIBC_PTHREAD   -o CMakeFiles/cmTC_c19dd.dir/src.c.o   -c /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp/src.c
Linking C executable cmTC_c19dd
/tmp/instance-11/output-1/host/bin/cmake -E cmake_link_script CMakeFiles/cmTC_c19dd.dir/link.txt --verbose=1
/usr/bin/gcc -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -Wno-comment -ffunction-sections -fdata-sections -DCMAKE_HAVE_LIBC_PTHREAD  -L/tmp/instance-11/output-1/host/lib -Wl,-rpath,/tmp/instance-11/output-1/host/lib  CMakeFiles/cmTC_c19dd.dir/src.c.o  -o cmTC_c19dd 
/usr/bin/ld: CMakeFiles/cmTC_c19dd.dir/src.c.o: in function `main':
src.c:(.text.startup.main+0x27): undefined reference to `pthread_create'
/usr/bin/ld: src.c:(.text.startup.main+0x30): undefined reference to `pthread_detach'
/usr/bin/ld: src.c:(.text.startup.main+0x3b): undefined reference to `pthread_join'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_c19dd.dir/build.make:87: cmTC_c19dd] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_c19dd/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:
#include <pthread.h>

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

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

  return 0;
}

Determining if the function pthread_create exists in the pthreads failed with the following output:
Change Dir: /tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_2c652/fast && make[1]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_2c652.dir/build.make CMakeFiles/cmTC_2c652.dir/build
make[2]: Entering directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_2c652.dir/CheckFunctionExists.c.o
/usr/bin/gcc   -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -Wno-comment -ffunction-sections -fdata-sections -DCHECK_FUNCTION_EXISTS=pthread_create   -o CMakeFiles/cmTC_2c652.dir/CheckFunctionExists.c.o   -c /tmp/instance-11/output-1/host/share/cmake-3.15/Modules/CheckFunctionExists.c
Linking C executable cmTC_2c652
/tmp/instance-11/output-1/host/bin/cmake -E cmake_link_script CMakeFiles/cmTC_2c652.dir/link.txt --verbose=1
/usr/bin/gcc -O2 -I/tmp/instance-11/output-1/host/include -fPIC -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wimplicit-fallthrough -Wno-comment -ffunction-sections -fdata-sections -DCHECK_FUNCTION_EXISTS=pthread_create  -L/tmp/instance-11/output-1/host/lib -Wl,-rpath,/tmp/instance-11/output-1/host/lib  CMakeFiles/cmTC_2c652.dir/CheckFunctionExists.c.o  -o cmTC_2c652 -lpthreads 
/usr/bin/ld: cannot find -lpthreads
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_2c652.dir/build.make:87: cmTC_2c652] Error 1
make[2]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_2c652/fast] Error 2
make[1]: Leaving directory '/tmp/instance-11/output-1/build/host-clang-9.0.1/buildroot-build/CMakeFiles/CMakeTmp'