In addition to numerous new and upgraded packages, this release has the following highlights: The GNOME version is now 3.24. The user handling now keeps track of deallocated UIDs/GIDs. When a user or group is revived, this allows it to be allocated the UID/GID it had before. A consequence is that UIDs and GIDs are no longer reused. The module option services.xserver.xrandrHeads now causes the first head specified in this list to be set as the primary head. Apart from that, it's now possible to also set additional options by using an attribute set, for example: { services.xserver.xrandrHeads = [ "HDMI-0" { output = "DVI-0"; primary = true; monitorConfig = '' Option "Rotate" "right" ''; } ]; } This will set the DVI-0 output to be the primary head, even though HDMI-0 is the first head in the list. The following new services were added since the last release: When upgrading from a previous release, please be aware of the following incompatible changes: aiccu package was removed. This is due to SixXS sunsetting its IPv6 tunnel. Top-level idea package collection was renamed. All JetBrains IDEs are now at jetbrains. flexget's state database cannot be upgraded to its new internal format, requiring removal of any existing db-config.sqlite which will be automatically recreated. The ipfs package now doesn't ignore the dataDir option anymore. If you've ever set this option to anything other than the default you'll have to either unset it (so the default gets used) or migrate the old data manually with dataDir=<valueOfDataDir> mv /var/lib/ipfs/.ipfs/* $dataDir rmdir /var/lib/ipfs/.ipfs The following changes apply if the stateVersion is changed to 17.09 or higher. For stateVersion = "17.03 or lower the old behavior is preserved. The postgres default version was changed from 9.5 to 9.6. The postgres superuser name has changed from root to postgres to more closely follow what other Linux distributions are doing. The postgres default dataDir has changed from /var/db/postgres to /var/lib/postgresql/$psqlSchema where $psqlSchema is 9.6 for example. The mysql default dataDir has changed from /var/mysql to /var/lib/mysql. Radicale's default package has changed from 1.x to 2.x. Instructions to migrate can be found here . It is also possible to use the newer version by setting the package to radicale2, which is done automatically when stateVersion is 17.09 or higher. The extraArgs option has been added to allow passing the data migration arguments specified in the instructions; see the radicale.nix NixOS test for an example migration. The caddy service was previously using an extra .caddy in the data directory specified with the dataDir option. The contents of the .caddy directory are now expected to be in the dataDir. The ssh-agent user service is not started by default anymore. Use programs.ssh.startAgent to enable it if needed. There is also a new programs.gnupg.agent module that creates a gpg-agent user service. It can also serve as a SSH agent if enableSSHSupport is set. The services.tinc.networks.<name>.listenAddress option had a misleading name that did not correspond to its behavior. It now correctly defines the ip to listen for incoming connections on. To keep the previous behaviour, use services.tinc.networks.<name>.bindToAddress instead. Refer to the description of the options for more details. tlsdate package and module were removed. This is due to the project being dead and not building with openssl 1.1. wvdial package and module were removed. This is due to the project being dead and not building with openssl 1.1. cc-wrapper's setup-hook now exports a number of environment variables corresponding to binutils binaries, (e.g. LD, STRIP, RANLIB, etc). This is done to prevent packages' build systems guessing, which is harder to predict, especially when cross-compiling. However, some packages have broken due to this—their build systems either not supporting, or claiming to support without adequate testing, taking such environment variables as parameters. services.firefox.syncserver now runs by default as a non-root user. To accomodate this change, the default sqlite database location has also been changed. Migration should work automatically. Refer to the description of the options for more details. The compiz window manager and package was removed. The system support had been broken for several years. Touchpad support should now be enabled through libinput as synaptics is now deprecated. See the option services.xserver.libinput.enable. grsecurity/PaX support has been dropped, following upstream's decision to cease free support. See upstream's announcement for more information. No complete replacement for grsecurity/PaX is available presently. The gnupg package used to suffix its programs with 2, like gpg2 and gpgv2. This suffix has since been dropped, and the programs are now simply gpg, gpgv, etc. Other notable improvements: Modules can now be disabled by using disabledModules, allowing another to take it's place. This can be used to import a set of modules from another channel while keeping the rest of the system on a stable release. Updated to FreeType 2.7.1, including a new TrueType engine. The new engine replaces the Infinality engine which was the default in NixOS. The default font rendering settings are now provided by fontconfig-penultimate, replacing fontconfig-ultimate; the new defaults are less invasive and provide rendering that is more consistent with other systems and hopefully with each font designer's intent. Some system-wide configuration has been removed from the Fontconfig NixOS module where user Fontconfig settings are available. ZFS/SPL have been updated to 0.7.0, zfsUnstable, splUnstable have therefore been removed. The time.timeZone option now allows the value null in addition to timezone strings. This value allows changing the timezone of a system imperatively using timedatectl set-timezone. The default timezone is still UTC. Nixpkgs overlays may now be specified with a file as well as a directory. The value of <nixpkgs-overlays> may be a file, and ~/.config/nixpkgs/overlays.nix can be used instead of the ~/.config/nixpkgs/overalys directory. See the overlays chapter of the Nixpkgs manual for more details. sha256 argument value of dockerTools.pullImage expression must be updated since the mechanism to download the image has been changed. Skopeo is now used to pull the image instead of the Docker daemon.