Hi, The documentation at [1] says that file names longer than 99 characters "are generally considered not to be portable in tarballs. See the tar-v7 and tar-ustar options below."
But [2] documents that this is only true for tar-v7, and that for tar-ustar filename-length-max=155 should be safe. This matters because now that (since Automake 1.18) the tar-ustar format is the default, for most packages there is no need to use filename-length-max=99 any more. They can use filename-length-max=151 instead. Bruno [1] https://www.gnu.org/software/automake/manual/html_node/List-of-Automake-options.html#index-filename_002dlength_002dmax_003d99 [2] https://www.gnu.org/software/automake/manual/html_node/List-of-Automake-options.html#tar_002dformats
