To build CRE, you first need to build the server and install it (
make install if running under Linux).
CRE sources are part of the server sources.
You need Qt5 and the associated development package.
Depending on your system, installing
qt5-default may be enough.
Once the server has been built and installed, from the server sources root:
cd utils/cre && qmake && make
This should build the tool, to run it:
should do the trick.