./autogen.sh --with-distro=LibreOfficeHaiku --enable-debug make -k -j4
-k is needed because unit tests crash. It makes the build system continue despite the fail.
LO_TRACE=Debugger bin/run svdemo
You need to decide on which arch you are going to work. This can be either x86 or x86_64. Have in mind that 32-bit OS has memory limitations and using Debugger is cumbersome - debug symbols are so big that it crashes during loading, so you either need to strip symbols from all the libraries you are not interested in, or use printf to debug.
Official x86_gcc2 hybrid is not tested, and I wouldn't recommend using it right now. The plan is to work on gcc2hybrid support when everything is tested and working on x86.
You need to have at least 30 GB of free disk space.
You can set up Haiku in a VM to build LO, but I would recommend using it on real hardware. VM's are really slow, and on hardware LO takes at least 6 hours to build.
Some unit tests crash. To avoid stopping the build process I recommend specifying default action the debug_server should take for cppunittester.
Script to build required packages for x86.