13.4.6 config.guess, config.sub at top level

You need to add the GNU config.guess and config.sub files to your distribution. They are needed because the AM_ICONV macro contains knowledge about specific platforms and therefore needs to identify the platform.

You can obtain the newest version of config.guess and config.sub from the ‘config’ project at https://savannah.gnu.org/. The commands to fetch them are

$ wget -O config.guess 'https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD'
$ wget -O config.sub 'https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD'

Less recent versions are also contained in the GNU automake and GNU libtool packages.

Normally, config.guess and config.sub are put at the top level of a distribution. But it is also possible to put them in a subdirectory, altogether with other configuration support files like install-sh, ltconfig, ltmain.sh or missing. All you need to do, other than moving the files, is to add the following line to your configure.ac.