Cannot specify the install directory when compiling from source

So it seem that in the latest Makefile the install location is overridden somewhere. I tried passing PREFIX or CMAKE_INSTALL_PREFIX as per docs, but it still install on the “install” directory.
The only way is to change the cmakecache file and recompile.
Anybody can have a look at it?

Forgot to say, I am using the latest branch-master.xml