Performing C++ SOURCE FILE Test HAVE_CXX_ATOMICS64_WITHOUT_LIB failed with the following output:
Change Dir: /tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_330d5/fast && make[1]: Entering directory '/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_330d5.dir/build.make CMakeFiles/cmTC_330d5.dir/build
make[2]: Entering directory '/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_330d5.dir/src.cxx.o
/tmp/instance-1/output-1/host/bin/nios2-linux-g++ --sysroot=/tmp/instance-1/output-1/host/nios2-buildroot-linux-gnu/sysroot    -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g2 -D_FORTIFY_SOURCE=1 -Wall -Wconversion -pedantic -Wextra -Wno-missing-field-initializers -DHAVE_CXX_ATOMICS64_WITHOUT_LIB -std=c++11   -o CMakeFiles/cmTC_330d5.dir/src.cxx.o -c /tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp/src.cxx
/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp/src.cxx: In function 'int main()':
/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp/src.cxx:6:12: warning: unused variable 'i' [-Wunused-variable]
    6 |   uint64_t i = x.load(std::memory_order_relaxed);
      |            ^
Linking CXX executable cmTC_330d5
/tmp/instance-1/output-1/host/bin/cmake -E cmake_link_script CMakeFiles/cmTC_330d5.dir/link.txt --verbose=1
/tmp/instance-1/output-1/host/bin/nios2-linux-g++ --sysroot=/tmp/instance-1/output-1/host/nios2-buildroot-linux-gnu/sysroot  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g2 -D_FORTIFY_SOURCE=1 -Wall -Wconversion -pedantic -Wextra -Wno-missing-field-initializers -DHAVE_CXX_ATOMICS64_WITHOUT_LIB -std=c++11    CMakeFiles/cmTC_330d5.dir/src.cxx.o  -o cmTC_330d5 
/tmp/instance-1/output-1/host/opt/ext-toolchain/bin/../lib/gcc/nios2-buildroot-linux-gnu/9.3.0/../../../../nios2-buildroot-linux-gnu/bin/ld: CMakeFiles/cmTC_330d5.dir/src.cxx.o: in function `std::__atomic_base<unsigned long long>::load(std::memory_order) const':
/tmp/instance-1/output-1/host/opt/ext-toolchain/nios2-buildroot-linux-gnu/include/c++/9.3.0/bits/atomic_base.h:419: undefined reference to `__atomic_load_8'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_330d5.dir/build.make:87: cmTC_330d5] Error 1
make[2]: Leaving directory '/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_330d5/fast] Error 2
make[1]: Leaving directory '/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp'


Source file was:

#include <atomic>
#include <cstdint>
std::atomic<uint64_t> x (0);
int main() {
  uint64_t i = x.load(std::memory_order_relaxed);
  return 0;
}

Performing C SOURCE FILE Test CMAKE_HAVE_LIBC_PTHREAD failed with the following output:
Change Dir: /tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_0a566/fast && make[1]: Entering directory '/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_0a566.dir/build.make CMakeFiles/cmTC_0a566.dir/build
make[2]: Entering directory '/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_0a566.dir/src.c.o
/tmp/instance-1/output-1/host/bin/nios2-linux-gcc --sysroot=/tmp/instance-1/output-1/host/nios2-buildroot-linux-gnu/sysroot   -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g2 -D_FORTIFY_SOURCE=1 -DCMAKE_HAVE_LIBC_PTHREAD   -o CMakeFiles/cmTC_0a566.dir/src.c.o   -c /tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp/src.c
Linking C executable cmTC_0a566
/tmp/instance-1/output-1/host/bin/cmake -E cmake_link_script CMakeFiles/cmTC_0a566.dir/link.txt --verbose=1
/tmp/instance-1/output-1/host/bin/nios2-linux-gcc --sysroot=/tmp/instance-1/output-1/host/nios2-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g2 -D_FORTIFY_SOURCE=1 -DCMAKE_HAVE_LIBC_PTHREAD    CMakeFiles/cmTC_0a566.dir/src.c.o  -o cmTC_0a566 -latomic 
/tmp/instance-1/output-1/host/opt/ext-toolchain/bin/../lib/gcc/nios2-buildroot-linux-gnu/9.3.0/../../../../nios2-buildroot-linux-gnu/bin/ld: CMakeFiles/cmTC_0a566.dir/src.c.o: undefined reference to symbol 'pthread_create@@GLIBC_2.21'
/tmp/instance-1/output-1/host/opt/ext-toolchain/bin/../lib/gcc/nios2-buildroot-linux-gnu/9.3.0/../../../../nios2-buildroot-linux-gnu/bin/ld: /tmp/instance-1/output-1/host/nios2-buildroot-linux-gnu/sysroot/lib/libpthread.so.0: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_0a566.dir/build.make:87: cmTC_0a566] Error 1
make[2]: Leaving directory '/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_0a566/fast] Error 2
make[1]: Leaving directory '/tmp/instance-1/output-1/build/pistache-f2f5a50fbfb5b8ef6cf1d3d2a9d442a8270e375d/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;
}