Performing C SOURCE FILE Test CMAKE_HAVE_LIBC_PTHREAD failed with the following output:
Change Dir: /home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_48892/fast && make[1]: Entering directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make  -f CMakeFiles/cmTC_48892.dir/build.make CMakeFiles/cmTC_48892.dir/build
make[2]: Entering directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_48892.dir/src.c.o
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/bin/sparc64-linux-gcc --sysroot=/home/giuliobenetti/autobuild/run/instance-0/output-1/host/sparc64-buildroot-linux-gnu/sysroot   -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -D_FORTIFY_SOURCE=1 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -DCMAKE_HAVE_LIBC_PTHREAD  -DNDEBUG   -std=c11 -o CMakeFiles/cmTC_48892.dir/src.c.o   -c /home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp/src.c
Linking C executable cmTC_48892
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/bin/cmake -E cmake_link_script CMakeFiles/cmTC_48892.dir/link.txt --verbose=1
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/bin/sparc64-linux-gcc --sysroot=/home/giuliobenetti/autobuild/run/instance-0/output-1/host/sparc64-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -D_FORTIFY_SOURCE=1 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -DCMAKE_HAVE_LIBC_PTHREAD  -DNDEBUG  -latomic  CMakeFiles/cmTC_48892.dir/src.c.o  -o cmTC_48892 
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/opt/ext-toolchain/bin/../lib/gcc/sparc64-buildroot-linux-gnu/9.3.0/../../../../sparc64-buildroot-linux-gnu/bin/ld: CMakeFiles/cmTC_48892.dir/src.c.o: undefined reference to symbol 'pthread_create@@GLIBC_2.2'
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/opt/ext-toolchain/bin/../lib/gcc/sparc64-buildroot-linux-gnu/9.3.0/../../../../sparc64-buildroot-linux-gnu/bin/ld: /home/giuliobenetti/autobuild/run/instance-0/output-1/host/sparc64-buildroot-linux-gnu/sysroot/lib64/libpthread.so.0: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_48892.dir/build.make:90: cmTC_48892] Error 1
make[2]: Leaving directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:124: cmTC_48892/fast] Error 2
make[1]: Leaving directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/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: /home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_c041a/fast && make[1]: Entering directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make  -f CMakeFiles/cmTC_c041a.dir/build.make CMakeFiles/cmTC_c041a.dir/build
make[2]: Entering directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_c041a.dir/CheckFunctionExists.c.o
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/bin/sparc64-linux-gcc --sysroot=/home/giuliobenetti/autobuild/run/instance-0/output-1/host/sparc64-buildroot-linux-gnu/sysroot   -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -D_FORTIFY_SOURCE=1 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -DCHECK_FUNCTION_EXISTS=pthread_create  -DNDEBUG   -std=c11 -o CMakeFiles/cmTC_c041a.dir/CheckFunctionExists.c.o   -c /home/giuliobenetti/autobuild/run/instance-0/output-1/host/share/cmake-3.16/Modules/CheckFunctionExists.c
Linking C executable cmTC_c041a
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/bin/cmake -E cmake_link_script CMakeFiles/cmTC_c041a.dir/link.txt --verbose=1
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/bin/sparc64-linux-gcc --sysroot=/home/giuliobenetti/autobuild/run/instance-0/output-1/host/sparc64-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -D_FORTIFY_SOURCE=1 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -DCHECK_FUNCTION_EXISTS=pthread_create  -DNDEBUG  -latomic  CMakeFiles/cmTC_c041a.dir/CheckFunctionExists.c.o  -o cmTC_c041a  -lpthreads 
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/opt/ext-toolchain/bin/../lib/gcc/sparc64-buildroot-linux-gnu/9.3.0/../../../../sparc64-buildroot-linux-gnu/bin/ld: cannot find -lpthreads
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_c041a.dir/build.make:90: cmTC_c041a] Error 1
make[2]: Leaving directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:124: cmTC_c041a/fast] Error 2
make[1]: Leaving directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/gnuradio-3.8.2.0/buildroot-build/CMakeFiles/CMakeTmp'