Вчера при обновлении Matuntu-X32-M112 (http://forum.matuntu.info/index.php?topic=417.msg2753#msg2753) в терминале и Synaptic было уведомление о не надёжных ключах сторонних репозиториев
Уведомления
W: gpgv:/var/lib/apt/lists/ppa.launchpad.net_cdemu_ppa_ubuntu_dists_xenial_InRelease: The repository is insufficiently signed by key AFDF4CC6A4F32AA9395FAE8F423A2125D782A00F (weak digest)
W: gpgv:/var/lib/apt/lists/ppa.launchpad.net_mc3man_mpv-tests_ubuntu_dists_xenial_InRelease: The repository is insufficiently signed by key 8E51A6D660CD88D67D65221D90BD7EACED8E640A (weak digest)
W: gpgv:/var/lib/apt/lists/ppa.launchpad.net_nemh_systemback_ubuntu_dists_xenial_InRelease: The repository is insufficiently signed by key 382003C2C8B7B4AB813E915B14E4942973C62A1B (weak digest)
W: gpgv:/var/lib/apt/lists/ppa.launchpad.net_otter-browser_release_ubuntu_dists_wily_InRelease: The repository is insufficiently signed by key 902176AF13D7C8F3E39E8882D33ACF5045A4FB57 (weak digest)
W: gpgv:/var/lib/apt/lists/ppa.launchpad.net_ricotz_docky_ubuntu_dists_xenial_InRelease: The repository is insufficiently signed by key 38AE4F60E356CE050312FA1775CFD31C9E5DB0C8 (weak digest)
W: gpgv:/var/lib/apt/lists/ppa.launchpad.net_ubuntu-mate-dev_xenial-mate_ubuntu_dists_xenial_InRelease: The repository is insufficiently signed by key 709A860A600B9A61FEF5346AFB01CC26162506E7 (weak digest)
W: gpgv:/var/lib/apt/lists/ppa.launchpad.net_yannubuntu_boot-repair_ubuntu_dists_xenial_InRelease: The repository is insufficiently signed by key 3C48D16124B50277AF10D27F32B18A1260D8DA0B (weak digest)
При этом обновления успешно установились.
Позднее установлено, что данная ситуация является багом Ubuntu 16.04 (https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1558331) и производных на её основе дистрибутивов.
Ждём исправления ситуации.