In general, the @TL{} build system uses the latest released versions of the GNU build tools, installed directly from the original GNU releases (e.g., by building them with @* @ @ @ @code{configure --prefix=/usr/local/gnu} @* and having @env{PATH} start with @file{/usr/local/gnu/bin}). Currently these are @example autoconf (GNU Autoconf) 2.69 automake (GNU automake) 1.14 ltmain.sh (GNU libtool) 2.4.2 bison (GNU Bison) 3.0 flex 2.5.37 m4 (GNU M4) 1.4.17 makeinfo (GNU texinfo) 5.2 @end example