RAR 5.0 format support needed, Your can see example for unpack code in to source tarball unrarsrc-5.7.4.tar.gz (ftp://Anonymous:[email protected]@ftp.rarlabs.com:21/rar/unrarsrc-5.7.4.tar.gz) on FTP RarLabs.com. Starting on Rar/WinRAR v5.00 (22.08.2013 year) RAR5 is default compression format fo rar archives (see WhatsNew.txt for details and have different in to RAR 2.9 (used up to Rar v2.5 - Rar v4.20 as default) format.

Please, update unarr library for support this Rar archive default format.