%%% src_install
The string with \Arg{rootprefix} means that block after check with \Prog{ause} method
will be executed, if project has word \Arg{rootprefix} in it.
In that case several essential packages are installed to root directory
\File{/} along with \File{/usr}.
When the system is merged to \File{/usr}, this block of code is not performed.
