%%% src_config
%@% IF pass1
The string with \Arg{crosstch} means that option \Opt{--host} is added to \Prog{configure},
if the project is built with cross-toolchain technology, introduced since \texttt{lfs-10.0}.
In that case the configuration of project contains word \Arg{crosstch},
which is checked by \Prog{ause\_enable}.
When the project is built with earlier \Arg{tools} technology, the word \Arg{crosstch} is absent
and option \Opt{--host} is not added.

%@% ELSE
The replacement of prefix to \Arg{tools} in original \texttt{lfs-9.*} is done in more universal way:

\begin{verbatim}
    replace="${PASS1PREFIX##/}"
    sed -i "s/usr/${replace}/"       build-aux/help2man
\end{verbatim}

First string gets the text part of the prefix, i.e. string \Arg{tools} from \Arg{/tools}.
The second string does the same change as original LFS does.
%@% END-IF

The string with \Arg{rootprefix} means that option \Opt{--bindir=/bin} is added to \Prog{configure},
if global project configuration has \Arg{rootprefix} in it and several essential packages are installed
to root directory \File{/} along with \File{/usr}.
When the system is merged to \File{/usr}, this option is not added.
