Determining if the LWS_WITH_MBEDTLS exist failed with the following output:
Change Dir: /test/ttyd/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_fb386/fast && /usr/bin/make -f CMakeFiles/cmTC_fb386.dir/build.make CMakeFiles/cmTC_fb386.dir/build
make[1]: Entering directory '/test/ttyd/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_fb386.dir/CheckSymbolExists.c.o
/usr/bin/cc  -I/usr/include/json-c  -D_GNU_SOURCE    -std=gnu99 -o CMakeFiles/cmTC_fb386.dir/CheckSymbolExists.c.o   -c /test/ttyd/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
/test/ttyd/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c: In function 'main':
/test/ttyd/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:8:19: error: 'LWS_WITH_MBEDTLS' undeclared (first use in this function); did you mean 'LWS_WITH_TLS'?
    8 |   return ((int*)(&LWS_WITH_MBEDTLS))[argc];
      |                   ^~~~~~~~~~~~~~~~
      |                   LWS_WITH_TLS
/test/ttyd/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:8:19: note: each undeclared identifier is reported only once for each function it appears in
make[1]: *** [CMakeFiles/cmTC_fb386.dir/build.make:66: CMakeFiles/cmTC_fb386.dir/CheckSymbolExists.c.o] Error 1
make[1]: Leaving directory '/test/ttyd/build/CMakeFiles/CMakeTmp'
make: *** [Makefile:121: cmTC_fb386/fast] Error 2


File /test/ttyd/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <lws_config.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef LWS_WITH_MBEDTLS
  return ((int*)(&LWS_WITH_MBEDTLS))[argc];
#else
  (void)argc;
  return 0;
#endif
}