Por que não usar o pacote unrar
não-livre?
$ apt-cache show unrar
Package: unrar
Priority: optional
Section: multiverse/utils
Installed-Size: 244
Maintainer: Ubuntu MOTU Developers <[email protected]>
Original-Maintainer: Martin Meredith <[email protected]>
Architecture: amd64
Source: unrar-nonfree
Version: 1:3.9.3-1
Depends: libc6 (>= 2.7), libgcc1 (>= 1:4.1.1), libstdc++6 (>= 4.1.1)
Conflicts: rar (<= 2.60-1)
Filename: pool/multiverse/u/unrar-nonfree/unrar_3.9.3-1_amd64.deb
Size: 102356
MD5sum: 992124eae32ccaba5e91d95dac4d4fa0
SHA1: df0526a43f0adc6ab5ef7848112fcad39bce877e
SHA256: b929a9b81891d76a93de9c0a2298f87bcc932d3991cfa1b0498bafa34ff0afe9
Description: Unarchiver for .rar files (non-free version)
Unrar can extract files from .rar archives. If you want to create .rar
archives, install package rar.
Homepage: http://www.rarlabs.com/
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Origin: Ubuntu
"nonfree" está relacionado à licença. A versão não-livre é mais recente que a versão sem-livre.