This pseudo-package does adjusting the toolchain without editing the filesystem directly.

It creates modificated spec files for gcc, which would be installed on top of the old ones.
Their location is calculated through \texttt{gcc --print-libgcc-file-name}, as in original LFS.
Here these files are located additionally inside \Envar{D} to create independent package.

The main additional trick here is reading the old unchrooted path to temporary tools from special file:
\begin{verbatim}
former_root="$(cat /var/lib/formerbase)"
\end{verbatim}

That file was written in another pseudo-package \Arg{basefiles}. The path must be removed from specs as well.
