OS X 0.92.3 CMAKE install problem

I successfully compiled and linked Inkscape 0.92.3 on OS X 10.11.6 using CMAKE with few code patches related to poppler 0.64 and a hack to use the right libiconv, the one from MacPorts and not the one from Xcode , using variable CMAKE_PREFIX_PATH="/opt/local".

But after "make install", the new inkscape executable cannot find its root directory, searching everything in the /share directory instead of /opt/local/share, the prefix /opt/local being missing, though CMAKE_INSTALL_PREFIX is set to /opt/local. I suppose I'm missing some other CMAKE variable(s) definition(s) I'm not aware of, but having very little knowledge about this tool, I wonder if someone could give me a clue as compiling and linking from scratch each time by try an error process is quite time consuming...

Any help appreciated and thanks in advance