Hello!
I am the person who has done the C/C++ Add-on 5.1 installer for Cubic IDE (http://www.softwareandcircuits.com/division/amiga/products/cubic/sdk.html). And I have now an Powerbook G4 (1.67 MHZ) with MoprhOS runing. I just now looking at the installer code of the script, and will ( i hope) make an another update, so the lates SDK for AmigaOS and MorphOS can be easy installed.

But i have too know how too unpack the .pack file on an MacOS Mawericks

I tried this: tar -x --xz -f /Desktop/MorphOS_2014/CUBIC_IDE_DEMO_2014/SDK-KITS/morphossdk/sdk.pack

But i gett an error for every file like this: Can't create 'Development/GG/bin/rcs2log'