Performing C SOURCE FILE Test HAVE_POSIX_SPAWN failed with the following output:
Change Dir: /home/lucas/fn_registry/build/wasm/runtime_test/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/gmake -f Makefile cmTC_3555d/fast && /usr/bin/gmake  -f CMakeFiles/cmTC_3555d.dir/build.make CMakeFiles/cmTC_3555d.dir/build
gmake[1]: Entering directory '/home/lucas/fn_registry/build/wasm/runtime_test/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_3555d.dir/src.c.o
/home/lucas/fn_registry/emsdk/upstream/emscripten/emcc -DHAVE_POSIX_SPAWN  -D_GNU_SOURCE=1 -fPIE -MD -MT CMakeFiles/cmTC_3555d.dir/src.c.o -MF CMakeFiles/cmTC_3555d.dir/src.c.o.d -o CMakeFiles/cmTC_3555d.dir/src.c.o -c /home/lucas/fn_registry/build/wasm/runtime_test/CMakeFiles/CMakeTmp/src.c
Linking C executable cmTC_3555d.js
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_3555d.dir/link.txt --verbose=1
/home/lucas/fn_registry/emsdk/upstream/emscripten/emcc   -D_GNU_SOURCE=1 CMakeFiles/cmTC_3555d.dir/src.c.o -o cmTC_3555d.js 
wasm-ld: error: CMakeFiles/cmTC_3555d.dir/src.c.o: undefined symbol: posix_spawnp
emcc: error: '/home/lucas/fn_registry/emsdk/upstream/bin/wasm-ld -o cmTC_3555d.wasm /tmp/tmpyqvec7cqlibemscripten_js_symbols.so --strip-debug --export=emscripten_stack_get_end --export=emscripten_stack_get_free --export=emscripten_stack_get_base --export=emscripten_stack_get_current --export=emscripten_stack_init --export=_emscripten_stack_alloc --export=__wasm_call_ctors --export=_emscripten_stack_restore --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-if-defined=__start_em_lib_deps --export-if-defined=__stop_em_lib_deps --export-if-defined=__start_em_js --export-if-defined=__stop_em_js --export-if-defined=main --export-if-defined=__main_argc_argv --export-if-defined=fflush --export-table -z stack-size=65536 --no-growable-memory --initial-heap=16777216 --no-entry --stack-first --table-base=1 CMakeFiles/cmTC_3555d.dir/src.c.o -L/home/lucas/fn_registry/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten -L/home/lucas/fn_registry/emsdk/upstream/emscripten/src/lib -lGL-getprocaddr -lal -lhtml5 -lstubs-debug -lnoexit -lc-debug -ldlmalloc-debug -lcompiler_rt -lc++-debug-noexcept -lc++abi-debug-noexcept -lsockets -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr' failed (returned 1)
gmake[1]: *** [CMakeFiles/cmTC_3555d.dir/build.make:100: cmTC_3555d.js] Error 1
gmake[1]: Leaving directory '/home/lucas/fn_registry/build/wasm/runtime_test/CMakeFiles/CMakeTmp'
gmake: *** [Makefile:127: cmTC_3555d/fast] Error 2


Source file was:

#include <spawn.h>
#include <unistd.h>

int main(void)
{
    int pipes[2];
    int pid;

    const char * args[] = {
      "/bin/false",
      NULL
    };

    const char * env[] = { NULL };

    pipe(pipes);

    posix_spawnattr_t attr;
    posix_spawn_file_actions_t fa;

    posix_spawnattr_init(&attr);
    posix_spawn_file_actions_init(&fa);

    posix_spawn_file_actions_addclose(&fa, pipes[0]);
    posix_spawn_file_actions_adddup2(&fa, pipes[1], STDOUT_FILENO);

    posix_spawn(&pid, args[0], &fa, &attr, (char * const *) args, (char * const *) env);
    posix_spawnp(&pid, args[0], &fa, &attr, (char * const *) args, (char * const *) env);

    posix_spawn_file_actions_destroy(&fa);
    posix_spawnattr_destroy(&attr);

    return 0;
}