XENIAL starting with all zstd packages installed: ii libzstd-dev 0.5.1-1 amd64 fast lossless compression algorithm -- development files ii libzstd0 0.5.1-1 amd64 fast lossless compression algorithm ii zstd 0.5.1-1 amd64 fast lossless compression algorithm -- CLI tool dist-upgrade: The following NEW packages will be installed: libzstd1 The following packages will be upgraded: zstd 1 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. results in: ii libzstd-dev 0.5.1-1 amd64 fast lossless compression algorithm -- development files ii libzstd0 0.5.1-1 amd64 fast lossless compression algorithm ii libzstd1 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm ii zstd 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm -- CLI tool Now installing the new dev package: root@xenial-zstd:~# apt install libzstd1-dev Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libfreetype6 libzstd0 Use 'apt autoremove' to remove them. The following packages will be REMOVED: libzstd-dev The following NEW packages will be installed: libzstd1-dev 0 upgraded, 1 newly installed, 1 to remove and 0 not upgraded. Results in: ii libzstd0 0.5.1-1 amd64 fast lossless compression algorithm ii libzstd1 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm ii libzstd1-dev 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm -- development files ii zstd 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm -- CLI tool Installing libzstd-dev removes libzstd1-dev: root@xenial-zstd:~# apt install libzstd-dev Reading package lists... Done Building dependency tree Reading state information... Done The following package was automatically installed and is no longer required: libfreetype6 Use 'apt autoremove' to remove it. The following packages will be REMOVED: libzstd1-dev The following NEW packages will be installed: libzstd-dev 0 upgraded, 1 newly installed, 1 to remove and 0 not upgraded. ==================================== RELEASE UPGRADE TO ARTFUL 1) starting with the 0.5.1 dev package in xenial: ii libzstd-dev 0.5.1-1 amd64 fast lossless compression algorithm -- development files ii libzstd0 0.5.1-1 amd64 fast lossless compression algorithm ii zstd 0.5.1-1 amd64 fast lossless compression algorithm -- CLI tool dist-upgrade to ppa version: ii libzstd-dev 0.5.1-1 amd64 fast lossless compression algorithm -- development files ii libzstd0 0.5.1-1 amd64 fast lossless compression algorithm ii libzstd1 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm ii zstd 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm -- CLI tool in the do-release-upgrade upgrade list: libzstd-dev libzstd1 zstd deemed obsolete and removed in the end: libzstd0 end result in artful: ii libzstd-dev 1.3.1+dfsg-1ubuntu0.1~ppa3 amd64 fast lossless compression algorithm -- development files ii libzstd1 1.3.1+dfsg-1ubuntu0.1~ppa3 amd64 fast lossless compression algorithm ii zstd 1.3.1+dfsg-1ubuntu0.1~ppa3 amd64 fast lossless compression algorithm -- CLI tool 2) starting with the 1.3.1 dev package in xenial: ii libzstd0 0.5.1-1 amd64 fast lossless compression algorithm ii libzstd1 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm ii libzstd1-dev 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm -- development files ii zstd 1.3.1+dfsg-1~ubuntu0.16.04.1~ppa5 amd64 fast lossless compression algorithm -- CLI tool do-release-upgrade stats: install list: libzstd-dev upgrade list: libzstd1 libzstd1-dev zstd remove (auto installed): libzstd0 end result: ii libzstd-dev 1.3.1+dfsg-1ubuntu0.1~ppa3 amd64 fast lossless compression algorithm -- development files ii libzstd1 1.3.1+dfsg-1ubuntu0.1~ppa3 amd64 fast lossless compression algorithm ii libzstd1-dev 1.3.1+dfsg-1ubuntu0.1~ppa3 amd64 transitional package for libzstd-dev ii zstd 1.3.1+dfsg-1ubuntu0.1~ppa3 amd64 fast lossless compression algorithm -- CLI tool