My reading is that it's out of space:
Oct 23 11:12:35 ubuntu ubiquity: dpkg : erreur de traitement de /target/var/cache/apt/archives/libx264-116_2%3a0.116.2042+git178455c-1ubuntu1_i386.deb (--unpack) : Oct 23 11:12:35 ubuntu ubiquity: échec en écriture lors d'une copie de buffer pour backend dpkg-deb pendant « ./usr/lib/i686/sse2/libx264.so.116 »: Aucun espace disponible sur le périphérique and google language tools says that's: dpkg: error processing / target/var/cache/apt/archives/libx264-116_2: 0.116.2042 git178455c- 1ubuntu1_i386.deb (- unpack): October 23 11:12:35 ubuntu ubiquity: failure during a write buffer to copy backend dpkg-deb for "./usr/lib/i686/sse2/libx264.so.116": No space left on device -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/880263 Title: installing operation stopped with "bug" message To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/880263/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
