CMake does not compile for QNX Neutrino due to wrong macro in json_writer.cpp
I am using QNX v7.1 and isfinite is not defined, therefore QNX requires the same define that any other target. The if statement below must be completely removed.
#if !(defined(__QNXNTO__)) // QNX already defines isfinite
#define isfinite std::isfinite
#endif