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This is needed to avoid this https://github.com/mesonbuild/meson/issues/13774 when we go back to making our subproject directory `src`.
97 lines
4.3 KiB
Markdown
97 lines
4.3 KiB
Markdown
# Release 1.2 (2012-12-06)
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This release has the following improvements and changes:
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- Nix has a new binary substituter mechanism: the *binary cache*. A
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binary cache contains pre-built binaries of Nix packages. Whenever
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Nix wants to build a missing Nix store path, it will check a set of
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binary caches to see if any of them has a pre-built binary of that
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path. The configuration setting `binary-caches` contains a list of
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URLs of binary caches. For instance, doing
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$ nix-env -i thunderbird --option binary-caches http://cache.nixos.org
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will install Thunderbird and its dependencies, using the available
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pre-built binaries in <http://cache.nixos.org>. The main advantage
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over the old “manifest”-based method of getting pre-built binaries
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is that you don’t have to worry about your manifest being in sync
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with the Nix expressions you’re installing from; i.e., you don’t
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need to run `nix-pull` to update your manifest. It’s also more
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scalable because you don’t need to redownload a giant manifest file
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every time.
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A Nix channel can provide a binary cache URL that will be used
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automatically if you subscribe to that channel. If you use the
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Nixpkgs or NixOS channels (<http://nixos.org/channels>) you
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automatically get the cache <http://cache.nixos.org>.
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Binary caches are created using `nix-push`. For details on the
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operation and format of binary caches, see the `nix-push` manpage.
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More details are provided in [this nix-dev
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posting](https://nixos.org/nix-dev/2012-September/009826.html).
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- Multiple output support should now be usable. A derivation can
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declare that it wants to produce multiple store paths by saying
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something like
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outputs = [ "lib" "headers" "doc" ];
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This will cause Nix to pass the intended store path of each output
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to the builder through the environment variables `lib`, `headers`
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and `doc`. Other packages can refer to a specific output by
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referring to `pkg.output`, e.g.
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buildInputs = [ pkg.lib pkg.headers ];
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If you install a package with multiple outputs using `nix-env`, each
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output path will be symlinked into the user environment.
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- Dashes are now valid as part of identifiers and attribute names.
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- The new operation `nix-store --repair-path` allows corrupted or
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missing store paths to be repaired by redownloading them. `nix-store
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--verify --check-contents
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--repair` will scan and repair all paths in the Nix store.
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Similarly, `nix-env`, `nix-build`, `nix-instantiate` and `nix-store
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--realise` have a `--repair` flag to detect and fix bad paths by
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rebuilding or redownloading them.
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- Nix no longer sets the immutable bit on files in the Nix store.
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Instead, the recommended way to guard the Nix store against
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accidental modification on Linux is to make it a read-only bind
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mount, like this:
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$ mount --bind /nix/store /nix/store
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$ mount -o remount,ro,bind /nix/store
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Nix will automatically make `/nix/store` writable as needed (using a
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private mount namespace) to allow modifications.
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- Store optimisation (replacing identical files in the store with hard
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links) can now be done automatically every time a path is added to
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the store. This is enabled by setting the configuration option
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`auto-optimise-store` to `true` (disabled by default).
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- Nix now supports `xz` compression for NARs in addition to `bzip2`.
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It compresses about 30% better on typical archives and decompresses
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about twice as fast.
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- Basic Nix expression evaluation profiling: setting the environment
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variable `NIX_COUNT_CALLS` to `1` will cause Nix to print how many
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times each primop or function was executed.
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- New primops: `concatLists`, `elem`, `elemAt` and `filter`.
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- The command `nix-copy-closure` has a new flag `--use-substitutes`
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(`-s`) to download missing paths on the target machine using the
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substitute mechanism.
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- The command `nix-worker` has been renamed to `nix-daemon`. Support
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for running the Nix worker in “slave” mode has been removed.
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- The `--help` flag of every Nix command now invokes `man`.
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- Chroot builds are now supported on systemd machines.
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This release has contributions from Eelco Dolstra, Florian Friesdorf,
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Mats Erik Andersson and Shea Levy.
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