When upgrading from a previous release, please be aware of the following incompatible changes: The default version of Apache httpd is now 2.4. If you use the extraConfig option to pass literal Apache configuration text, you may need to update it — see Apache’s documentation for details. If you wish to continue to use httpd 2.2, add the following line to your NixOS configuration: services.httpd.package = pkgs.apacheHttpd_2_2; PHP 5.3 has been removed because it is no longer supported by the PHP project. A migration guide is available. The host side of a container virtual Ethernet pair is now called ve-container-name rather than c-container-name. GNOME 3.10 support has been dropped. The default GNOME version is now 3.12. The system-wide default timezone for NixOS installations changed from CET to UTC. To choose a different timezone for your system, configure time.timeZone in configuration.nix. A fairly complete list of possible values for that setting is available at . GNU screen has been updated to 4.2.1, which breaks the ability to connect to sessions created by older versions of screen.