If you use a mac with Homebrew, there already is a formula to install dspdfviewer
The previous command installs the latest release. If you want to test out the newest features, provide the head option:
If you want to compile from source, please read the generic install instructions about the available cmake-time switches.
If you installed Qt5 via Homebrew, you will have
to pass its installation prefix to
cmake /path/to/source -DSomeOption=ON -DCMAKE_PREFIX_PATH=$(brew --prefix qt5)