The planning step is the most important part in successfully creating a working package. Before writing the XML create a step-by-step list of how the software is installed. If possible, walk through the installation in a clean /bin/bash environment, since this will more realistically reflect the environment in which ReST will install the software. Once this list has been written, place a mark next to each command that would not need to be run on every machine in an homogeneous environment with a shared filesystem. Now note command options that should be offered for each command, for example ./configure --with-foo. Try installing the software by walking through this list one command at a time; if it works without problem then fewer problems are likely to occur when the package is written.