In this case it's enough to put quotes around those flags (like in lines 54/55) - CMake joins items with semicolon as a separator which results in the following error message:

```/usr/bin/c++   -DNETWORK_ENABLE_HTTPS -std=c++11;-Wall (...)
c++: fatal error: no input files
compilation terminated.
/bin/sh: 1: -Wall: not found````