Determining if the pthread_create exist failed with the following output: Change Dir: /home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp Run Build Command:"/usr/bin/gmake" "cmTC_351d3/fast" gmake[1]: Entering directory '/home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp' /usr/bin/gmake -f CMakeFiles/cmTC_351d3.dir/build.make CMakeFiles/cmTC_351d3.dir/build gmake[2]: Entering directory '/home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp' Building C object CMakeFiles/cmTC_351d3.dir/CheckSymbolExists.c.o /home/naourr/work/instance-1/output/host/bin/x86_64-ctng_locales-linux-gnu-gcc --sysroot=/home/naourr/work/instance-1/output/host/x86_64-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -std=gnu99 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -DNDEBUG -o CMakeFiles/cmTC_351d3.dir/CheckSymbolExists.c.o -c /home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c Linking C executable cmTC_351d3 /usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_351d3.dir/link.txt --verbose=1 /home/naourr/work/instance-1/output/host/bin/x86_64-ctng_locales-linux-gnu-gcc --sysroot=/home/naourr/work/instance-1/output/host/x86_64-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -std=gnu99 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -DNDEBUG -rdynamic CMakeFiles/cmTC_351d3.dir/CheckSymbolExists.c.o -o cmTC_351d3 CMakeFiles/cmTC_351d3.dir/CheckSymbolExists.c.o: In function `main': CheckSymbolExists.c:(.text.startup+0x6): undefined reference to `pthread_create' collect2: error: ld returned 1 exit status gmake[2]: *** [CMakeFiles/cmTC_351d3.dir/build.make:87: cmTC_351d3] Error 1 gmake[2]: Leaving directory '/home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp' gmake[1]: *** [Makefile:126: cmTC_351d3/fast] Error 2 gmake[1]: Leaving directory '/home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp' File /home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c: /* */ #include int main(int argc, char** argv) { (void)argv; #ifndef pthread_create return ((int*)(&pthread_create))[argc]; #else (void)argc; return 0; #endif } Determining if the function pthread_create exists in the pthreads failed with the following output: Change Dir: /home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp Run Build Command:"/usr/bin/gmake" "cmTC_8f55a/fast" gmake[1]: Entering directory '/home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp' /usr/bin/gmake -f CMakeFiles/cmTC_8f55a.dir/build.make CMakeFiles/cmTC_8f55a.dir/build gmake[2]: Entering directory '/home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp' Building C object CMakeFiles/cmTC_8f55a.dir/CheckFunctionExists.c.o /home/naourr/work/instance-1/output/host/bin/x86_64-ctng_locales-linux-gnu-gcc --sysroot=/home/naourr/work/instance-1/output/host/x86_64-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -std=gnu99 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -DCHECK_FUNCTION_EXISTS=pthread_create -DNDEBUG -o CMakeFiles/cmTC_8f55a.dir/CheckFunctionExists.c.o -c /usr/share/cmake/Modules/CheckFunctionExists.c Linking C executable cmTC_8f55a /usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_8f55a.dir/link.txt --verbose=1 /home/naourr/work/instance-1/output/host/bin/x86_64-ctng_locales-linux-gnu-gcc --sysroot=/home/naourr/work/instance-1/output/host/x86_64-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -std=gnu99 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -DCHECK_FUNCTION_EXISTS=pthread_create -DNDEBUG -rdynamic CMakeFiles/cmTC_8f55a.dir/CheckFunctionExists.c.o -o cmTC_8f55a -lpthreads /home/naourr/work/instance-1/output/host/opt/ext-toolchain/bin/../lib/gcc/x86_64-ctng_locales-linux-gnu/4.8.2/../../../../x86_64-ctng_locales-linux-gnu/bin/ld: cannot find -lpthreads collect2: error: ld returned 1 exit status gmake[2]: *** [CMakeFiles/cmTC_8f55a.dir/build.make:87: cmTC_8f55a] Error 1 gmake[2]: Leaving directory '/home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp' gmake[1]: *** [Makefile:126: cmTC_8f55a/fast] Error 2 gmake[1]: Leaving directory '/home/naourr/work/instance-1/output/build/gnuradio-3.7.13.3/buildroot-build/CMakeFiles/CMakeTmp'