NixOS Release Notes: Service, Package, and Build System Updates

- The `security.rngd` service is now disabled by default. This choice was made because there's krngd in the linux kernel space making it (for most usecases) functionally redundant. - The `hardware.nvidia.optimus_prime.enable` service has been renamed to `hardware.nvidia.prime.sync.enable` and has many new enhancements. Related nvidia prime settings may have also changed. - The package nextcloud17 has been removed and nextcloud18 was marked as insecure since both of them will [ will be EOL (end of life) within the lifetime of 20.09](https://docs.nextcloud.com/server/19/admin_manual/release_schedule.html). It's necessary to upgrade to nextcloud19: - From nextcloud17, you have to upgrade to nextcloud18 first as Nextcloud doesn't allow going multiple major revisions forward in a single upgrade. This is possible by setting [services.nextcloud.package](options.html#opt-services.nextcloud.package) to nextcloud18. - From nextcloud18, it's possible to directly upgrade to nextcloud19 by setting [services.nextcloud.package](options.html#opt-services.nextcloud.package) to nextcloud19. - The GNOME desktop manager no longer default installs gnome3.epiphany. It was chosen to do this as it has a usability breaking issue (see issue [\#98819](https://github.com/NixOS/nixpkgs/issues/98819)) that makes it unsuitable to be a default app. ::: {.note} Issue [\#98819](https://github.com/NixOS/nixpkgs/issues/98819) is now fixed and gnome3.epiphany is once again installed by default. ::: - If you want to manage the configuration of wpa_supplicant outside of NixOS you must ensure that none of [networking.wireless.networks](options.html#opt-networking.wireless.networks), [networking.wireless.extraConfig](options.html#opt-networking.wireless.extraConfig) or [networking.wireless.userControlled.enable](options.html#opt-networking.wireless.userControlled.enable) is being used or `true`. Using any of those options will cause wpa_supplicant to be started with a NixOS generated configuration file instead of your own. ## Other Notable Changes {#sec-release-20.09-notable-changes} - SD images are now compressed by default using `zstd`. The compression for ISO images has also been changed to `zstd`, but ISO images are still not compressed by default. - `services.journald.rateLimitBurst` was updated from `1000` to `10000` to follow the new upstream systemd default. - The notmuch package moves its emacs-related binaries and emacs lisp files to a separate output. They're not part of the default `out` output anymore - if you relied on the `notmuch-emacs-mua` binary or the emacs lisp files, access them via the `notmuch.emacs` output. - Device tree overlay support was improved in [\#79370](https://github.com/NixOS/nixpkgs/pull/79370) and now uses [hardware.deviceTree.kernelPackage](options.html#opt-hardware.deviceTree.kernelPackage) instead of `hardware.deviceTree.base`. [hardware.deviceTree.overlays](options.html#opt-hardware.deviceTree.overlays) configuration was extended to support `.dts` files with symbols. Device trees can now be filtered by setting [hardware.deviceTree.filter](options.html#opt-hardware.deviceTree.filter) option. - The default output of `buildGoPackage` is now `$out` instead of `$bin`. - `buildGoModule` `doCheck` now defaults to `true`. - Packages built using `buildRustPackage` now use `release` mode for the `checkPhase` by default. Please note that Rust packages utilizing a custom build/install procedure (e.g. by using a `Makefile`) or test suites that rely on the structure of the `target/` directory may break due to those assumptions. For further information, please read the Rust section in the Nixpkgs manual. - The cc- and binutils-wrapper's "infix salt" and `_BUILD_` and `_TARGET_` user infixes have been replaced with with a "suffix salt" and suffixes and `_FOR_BUILD` and `_FOR_TARGET`. This matches the autotools convention for env vars which standard for these things, making interfacing with other tools easier.

NixOS updates: `security.rngd` is now disabled by default due to kernel redundancy. NVIDIA Prime's `hardware.nvidia.optimus_prime.enable` is renamed to `hardware.nvidia.prime.sync.enable`. Nextcloud 17/18 are deprecated; upgrade to Nextcloud 19 is required, potentially in stages from v17. GNOME Epiphany was temporarily removed but reinstated. For external wpa_supplicant config, avoid specific NixOS `networking.wireless` options. SD images now use `zstd` compression. `services.journald.rateLimitBurst` increased. `notmuch` Emacs files moved to a separate output. Device tree overlay support is improved. Build system changes include: `buildGoPackage` defaults output to `$out`; `buildGoModule`'s `doCheck` defaults to `true`; `buildRustPackage` `checkPhase` defaults to `release` mode (note custom build impacts); and cc/binutils-wrappers now use suffix salts and `_FOR_BUILD`/`_FOR_TARGET` for better compatibility.