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Diffstat (limited to 'doc/manual/src')
| -rw-r--r-- | doc/manual/src/release-notes/rl-2.4.md | 506 |
1 files changed, 498 insertions, 8 deletions
diff --git a/doc/manual/src/release-notes/rl-2.4.md b/doc/manual/src/release-notes/rl-2.4.md index f7ab9f6ad..def4a7b66 100644 --- a/doc/manual/src/release-notes/rl-2.4.md +++ b/doc/manual/src/release-notes/rl-2.4.md @@ -1,8 +1,498 @@ -# Release 2.4 (202X-XX-XX) - - - It is now an error to modify the `plugin-files` setting via a - command-line flag that appears after the first non-flag argument - to any command, including a subcommand to `nix`. For example, - `nix-instantiate default.nix --plugin-files ""` must now become - `nix-instantiate --plugin-files "" default.nix`. - - Plugins that add new `nix` subcommands are now actually respected. +# Release 2.4 (2021-10-XX) + +This is the first release in more than two years and is the result of +more than 2800 commits from 195 contributors since release 2.3. + +## Highlights + +* Nix's **error messages** have been improved a lot. For instance, + evaluation errors now point out the location of the error: + + ``` + $ nix build + error: undefined variable 'bzip3' + + at /nix/store/449lv242z0zsgwv95a8124xi11sp419f-source/flake.nix:88:13: + + 87| [ curl + 88| bzip3 xz brotli editline + | ^ + 89| openssl sqlite + ``` + +* The **`nix` command** has seen a lot of work and is now almost at + feature parity with the old command-line interface (the `nix-*` + commands). It aims to be [more modern, consistent and pleasant to + use](../contributing/cli-guideline.md) than the old CLI. It is still + marked as experimental but its interface should not change much + anymore in future releases. + +* **Flakes** are a new format to package Nix-based projects in a more + discoverable, composable, consistent and reproducible way. A flake + is just a repository or tarball containing a file named `flake.nix` + that specifies dependencies on other flakes and returns any Nix + assets such as packages, Nixpkgs overlays, NixOS modules or CI + tests. The new `nix` CLI is primarily based around flakes; for + example, a command like `nix run nixpkgs#hello` runs the `hello` + application from the `nixpkgs` flake. + + Flakes are currently marked as experimental. For an introduction, + see [this blog + post](https://www.tweag.io/blog/2020-05-25-flakes/). For detailed + information about flake syntax and semantics, see the [`nix flake` + manual page](../command-ref/new-cli/nix3-flake.md). + +* Nix's store can now be **content-addressed**, meaning that the hash + component of a store path is the hash of the path's + contents. Previously Nix could only build **input-addressed** store + paths, where the hash is computed from the derivation dependency + graph. Content-addressing allows deduplication, early cutoff in + build systems, and unprivileged closure copying. This is still [an + experimental + feature](https://discourse.nixos.org/t/content-addressed-nix-call-for-testers/12881). + +* The Nix manual has been converted into Markdown, making it easier to + contribute. In addition, every `nix` subcommand now has a manual + page, documenting every option. + +* A new setting that allows **experimental features** to be enabled + selectively. This allows us to merge unstable features into Nix more + quickly and do more frequent releases. + +## Other features + +* There are many new `nix` subcommands: + + - `nix develop` is intended to replace `nix-shell`. It has a number + of new features: + + * It automatically sets the output environment variables (such as + `$out`) to writable locations (such as `./outputs/out`). + + * It can store the environment in a profile. This is useful for + offline work. + + * It can run specific phases directly. For instance, `nix develop + --build` runs `buildPhase`. + + - It allows dependencies in the Nix store to be "redirected" to + arbitrary directories using the `--redirect` flag. This is + useful if you want to hack on a package *and* some of its + dependencies at the same time. + + - `nix print-dev-env` prints the environment variables and bash + functions defined by a derivation. This is useful for users of + other shells than bash (especially with `--json`). + + - `nix shell` was previously named `nix run` and is intended to + replace `nix-shell -p`, but without the `stdenv` overhead. It + simply starts a shell where some packages have been added to + `$PATH`. + + - `nix run` (not to be confused with the old subcommand that has + been renamed to `nix shell`) runs an "app", a flake output that + specifies a command to run, or an eponymous program from a + package. For example, `nix run nixpkgs#hello` runs the `hello` + program from the `hello` package in `nixpkgs`. + + - `nix flake` is the container for flake-related operations, such as + creating a new flake, querying the contents of a flake or updating + flake lock files. + + - `nix registry` allows you to query and update the flake registry, + which maps identifiers such as `nixpkgs` to concrete flake URLs. + + - `nix profile` is intended to replace `nix-env`. Its main advantage + is that it keeps track of the provenance of installed packages + (e.g. exactly which flake version a package came from). It also + has some helpful subcommands: + + * `nix profile history` shows what packages were added, upgraded + or removed between each version of a profile. + + * `nix profile diff-closures` shows the changes between the + closures of each version of a profile. This allows you to + discover the addition or removal of dependencies or size + changes. + + **Warning**: after a profile has been updated using `nix profile`, + it is no longer usable with `nix-env`. + + - `nix store diff-closures` shows the differences between the + closures of two store paths in terms of the versions and sizes of + dependencies in the closures. + + - `nix store make-content-addressable` rewrites an arbitrary closure + to make it content-addressed. Such paths can be copied into other + stores without requiring signatures. + + - `nix bundle` uses the [`nix-bundle` + program](https://github.com/matthewbauer/nix-bundle) to convert a + closure into a self-extracting executable. + + - Various other replacements for the old CLI, e.g. `nix store gc`, + `nix store delete`, `nix store repair`, `nix nar dump-path`, `nix + store prefetch-file`, `nix store prefetch-tarball`, `nix key` and + `nix daemon`. + +* Nix now has an **evaluation cache** for flake outputs. For example, + a second invocation of the command `nix run nixpkgs#firefox` will + not need to evaluate the `firefox` attribute because it's already in + the evaluation cache. This is made possible by the hermetic + evaluation model of flakes. + +* The new `--offline` flag disables substituters and causes all + locally cached tarballs and repositories to be considered + up-to-date. + +* The new `--refresh` flag causes all locally cached tarballs and + repositories to be considered out-of-date. + +* Many `nix` subcommands now have a `--json` option to produce + machine-readable output. + +* `nix repl` has a new `:doc` command to show documentation about + builtin functions (e.g. `:doc builtins.map`). + +* Binary cache stores now have an option `index-debug-info` to create + an index of DWARF debuginfo files for use by + [`dwarffs`](https://github.com/edolstra/dwarffs). + +* To support flakes, Nix now has an extensible mechanism for fetching + source trees. Currently it has the following backends: + + * Git repositories + + * Mercurial repositories + + * GitHub and GitLab repositories (an optimisation for faster + fetching than Git) + + * Tarballs + + * Arbitrary directories + + The fetcher infrastructure is exposed via flake input specifications + and via the `fetchTree` built-in. + +* **Languages changes**: the only new language feature is that you can + now have antiquotations in paths, e.g. `./${foo}` instead of `./. + + foo`. + +* **New built-in functions**: + + - `builtins.fetchTree` allows fetching a source tree using any + backends supported by the fetcher infrastructure. It subsumes the + functionality of existing built-ins like `fetchGit`, + `fetchMercurial` and `fetchTarball`. + + - `builtins.getFlake` fetches a flake and returns its output + attributes. This function should not be used inside flakes! Use + flake inputs instead. + + - `builtins.floor` and `builtins.ceil` round a floating-point number + down and up, respectively. + +* Experimental support for recursive Nix. This means that Nix + derivations can now call Nix to build other derivations. This is not + in a stable state yet and not well + [documented](https://github.com/NixOS/nix/commit/c4d7c76b641d82b2696fef73ce0ac160043c18da). + +* The new experimental feature `no-url-literals` disables URL + literals. This helps to implement [RFC + 45](https://github.com/NixOS/rfcs/pull/45). + +* Nix now uses `libarchive` to decompress and unpack tarballs and zip + files, so `tar` is no longer required. + +* The priority of substituters can now be overridden using the + `priority` substituter setting (e.g. `--substituters + 'http://cache.nixos.org?priority=100 daemon?priority=10'`). + +* `nix edit` now supports non-derivation attributes, e.g. `nix edit + .#nixosConfigurations.bla`. + +* The `nix` command now provides command line completion for `bash`, + `zsh` and `fish`. Since the support for getting completions is built + into `nix`, it's easy to add support for other shells. + +* The new `--log-format` flag selects what Nix's output looks like. It + defaults to a terse progress indicator. There is a new + `internal-json` output format for use by other programs. + +* `nix eval` has a new `--apply` flag that applies a function to the + evaluation result. + +* `nix eval` has a new `--write-to` flag that allows it to write a + nested attribute set of string leaves to a corresponding directory + tree. + +* Memory improvements: many operations that add paths to the store or + copy paths between stores now run in constant memory. + +* Many `nix` commands now support the flag `--derivation` to operate + on a `.drv` file itself instead of its outputs. + +* There is a new store called `dummy://` that does not support + building or adding paths. This is useful if you want to use the Nix + evaluator but don't have a Nix store. + +* The `ssh-ng://` store now allows substituting paths on the remote, + as `ssh://` already did. + +* When auto-calling a function with an ellipsis, all arguments are now + passed. + +* New `nix-shell` features: + + - It preserves the `PS1` environment variable if + `NIX_SHELL_PRESERVE_PROMPT` is set. + + - With `-p`, it passes any `--arg`s as Nixpkgs arguments. + + - Support for structured attributes. + +* `nix-prefetch-url` has a new `--executable` flag. + +* On `x86_64` systems, [`x86_64` microarchitecture + levels](https://lwn.net/Articles/844831/) are mapped to additional + system types (e.g. `x86_64-v1-linux`). + +* The new `--eval-store` flag allows you to use a different store for + evaluation than for building or storing the build result. This is + primarily useful when you want to query whether something exists in + a read-only store, such as a binary cache: + + ``` + # nix path-info --json --store https://cache.nixos.org \ + --eval-store auto nixpkgs#hello + ``` + + (Here `auto` indicates the local store.) + +* The Nix daemon has a new low-latency mechanism for copying + closures. This is useful when building on remote stores such as + `ssh-ng://`. + +* Plugins can now register `nix` subcommands. + +## Incompatible changes + +* The `nix` command is now marked as an experimental feature. This + means that you need to add + + > experimental-features = nix-command + + to your `nix.conf` if you want to use it, or pass + `--extra-experimental-features nix-command` on the command line. + +* The old `nix run` has been renamed to `nix shell` (and there is a + new `nix run` that does something else, as described above). + +* It is now an error to modify the `plugin-files` setting via a + command-line flag that appears after the first non-flag argument to + any command, including a subcommand to `nix`. For example, + `nix-instantiate default.nix --plugin-files ""` must now become + `nix-instantiate --plugin-files "" default.nix`. + +* We no longer release source tarballs. If you want to build from + source, please build from the tags in the Git repository. + +## Contributors + +This release has contributions from +Adam Höse, +Albert Safin, +Alex Kovar, +Alex Zero, +Alexander Bantyev, +Alexandre Esteves, +Alyssa Ross, +Anatole Lucet, +Anders Kaseorg, +Andreas Rammhold, +Antoine Eiche, +Antoine Martin, +Arnout Engelen, +Arthur Gautier, +aszlig, +Ben Burdette, +Benjamin Hipple, +Bernardo Meurer, +Björn Gohla, +Bjørn Forsman, +Bob van der Linden, +Brian Leung, +Brian McKenna, +Brian Wignall, +Bruce Toll, +Bryan Richter, +Calle Rosenquist, +Calvin Loncaric, +Carlo Nucera, +Carlos D'Agostino, +Chaz Schlarp, +Christian Höppner, +Christian Kampka, +Chua Hou, +Chuck, +Cole Helbling, +Daiderd Jordan, +Dan Callahan, +Dani, +Daniel Fitzpatrick, +Danila Fedorin, +Daniël de Kok, +Danny Bautista, +DavHau, +David McFarland, +Dima, +Domen Kožar, +Dominik Schrempf, +Dominique Martinet, +dramforever, +Dustin DeWeese, +edef, +Eelco Dolstra, +Emilio Karakey, +Emily, +Eric Culp, +Ersin Akinci, +Fabian Möller, +Farid Zakaria, +Federico Pellegrin, +Finn Behrens, +Florian Franzen, +Félix Baylac-Jacqué, +Gabriel Gonzalez, +Geoff Reedy, +Georges Dubus, +Graham Christensen, +Greg Hale, +Greg Price, +Gregor Kleen, +Gregory Hale, +Griffin Smith, +Guillaume Bouchard, +Harald van Dijk, +illustris, +Ivan Zvonimir Horvat, +Jade, +Jake Waksbaum, +jakobrs, +James Ottaway, +Jan Tojnar, +Janne Heß, +Jaroslavas Pocepko, +Jarrett Keifer, +Jeremy Schlatter, +Joachim Breitner, +Joe Hermaszewski, +Joe Pea, +John Ericson, +Jonathan Ringer, +Josef Kemetmüller, +Joseph Lucas, +Jude Taylor, +Julian Stecklina, +Julien Tanguy, +Jörg Thalheim, +Kai Wohlfahrt, +keke, +Keshav Kini, +Kevin Quick, +Kevin Stock, +Kjetil Orbekk, +Krzysztof Gogolewski, +kvtb, +Lars Mühmel, +Leonhard Markert, +Lily Ballard, +Linus Heckemann, +Lorenzo Manacorda, +Lucas Desgouilles, +Lucas Franceschino, +Lucas Hoffmann, +Luke Granger-Brown, +Madeline Haraj, +Marwan Aljubeh, +Mat Marini, +Mateusz Piotrowski, +Matthew Bauer, +Matthew Kenigsberg, +Mauricio Scheffer, +Maximilian Bosch, +Michael Adler, +Michael Bishop, +Michael Fellinger, +Michael Forney, +Michael Reilly, +mlatus, +Mykola Orliuk, +Nathan van Doorn, +Naïm Favier, +ng0, +Nick Van den Broeck, +Nicolas Stig124 Formichella, +Niels Egberts, +Niklas Hambüchen, +Nikola Knezevic, +oxalica, +p01arst0rm, +Pamplemousse, +Patrick Hilhorst, +Paul Opiyo, +Pavol Rusnak, +Peter Kolloch, +Philipp Bartsch, +Philipp Middendorf, +Piotr Szubiakowski, +Profpatsch, +Puck Meerburg, +Ricardo M. Correia, +Rickard Nilsson, +Robert Hensing, +Robin Gloster, +Rodrigo, +Rok Garbas, +Ronnie Ebrin, +Rovanion Luckey, +Ryan Burns, +Ryan Mulligan, +Ryne Everett, +Sam Doshi, +Sam Lidder, +Samir Talwar, +Samuel Dionne-Riel, +Sebastian Ullrich, +Sergei Trofimovich, +Sevan Janiyan, +Shao Cheng, +Shea Levy, +Silvan Mosberger, +Stefan Frijters, +Stefan Jaax, +sternenseemann, +Steven Shaw, +Stéphan Kochen, +SuperSandro2000, +Suraj Barkale, +Taeer Bar-Yam, +Thomas Churchman, +Théophane Hufschmitt, +Timothy DeHerrera, +Timothy Klim, +Tobias Möst, +Tobias Pflug, +Tom Bereknyei, +Travis A. Everett, +Ujjwal Jain, +Vladimír Čunát, +Wil Taylor, +Will Dietz, +Yaroslav Bolyukin, +Yestin L. Harrison, +YI, +Yorick van Pelt, +Yuriy Taraday and +zimbatm. |