Performing C++ SOURCE FILE Test BUILTIN_ATOMIC failed with the following output:
Change Dir: /home/thomas/autobuild/instance-3/output-1/build/z3-4.12.1/buildroot-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make -f Makefile cmTC_e5a4c/fast && make[1]: Entering directory '/home/thomas/autobuild/instance-3/output-1/build/z3-4.12.1/buildroot-build/CMakeFiles/CMakeTmp'
/usr/bin/make  -f CMakeFiles/cmTC_e5a4c.dir/build.make CMakeFiles/cmTC_e5a4c.dir/build
make[2]: Entering directory '/home/thomas/autobuild/instance-3/output-1/build/z3-4.12.1/buildroot-build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_e5a4c.dir/src.cxx.o
/home/thomas/autobuild/instance-3/output-1/host/bin/or1k-buildroot-linux-musl-g++ --sysroot=/home/thomas/autobuild/instance-3/output-1/host/or1k-buildroot-linux-musl/sysroot -DBUILTIN_ATOMIC  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -Werror=odr    -DNDEBUG -o CMakeFiles/cmTC_e5a4c.dir/src.cxx.o -c /home/thomas/autobuild/instance-3/output-1/build/z3-4.12.1/buildroot-build/CMakeFiles/CMakeTmp/src.cxx
Linking CXX executable cmTC_e5a4c
/home/thomas/autobuild/instance-3/output-1/host/bin/cmake -E cmake_link_script CMakeFiles/cmTC_e5a4c.dir/link.txt --verbose=1
/home/thomas/autobuild/instance-3/output-1/host/bin/or1k-buildroot-linux-musl-g++ --sysroot=/home/thomas/autobuild/instance-3/output-1/host/or1k-buildroot-linux-musl/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g0 -Werror=odr    -DNDEBUG CMakeFiles/cmTC_e5a4c.dir/src.cxx.o -o cmTC_e5a4c 
/home/thomas/autobuild/instance-3/output-1/host/lib/gcc/or1k-buildroot-linux-musl/10.4.0/../../../../or1k-buildroot-linux-musl/bin/ld: CMakeFiles/cmTC_e5a4c.dir/src.cxx.o: in function `main':
src.cxx:(.text.startup+0xb4): undefined reference to `__atomic_fetch_add_8'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_e5a4c.dir/build.make:99: cmTC_e5a4c] Error 1
make[2]: Leaving directory '/home/thomas/autobuild/instance-3/output-1/build/z3-4.12.1/buildroot-build/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:127: cmTC_e5a4c/fast] Error 2
make[1]: Leaving directory '/home/thomas/autobuild/instance-3/output-1/build/z3-4.12.1/buildroot-build/CMakeFiles/CMakeTmp'


Source file was:

#include <atomic>
std::atomic<int> x;
std::atomic<short> y;
std::atomic<char> z;
std::atomic<long long> w;
int main() {
	++z;
	++y;
    ++w;
	return ++x;
}