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Fix some dangling references
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@ -1,33 +1,32 @@
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# Tuning Cores and Jobs
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Nix has two relevant settings with regards to how your CPU cores will be
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utilized: [???](#conf-cores) and [???](#conf-max-jobs). This chapter
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will talk about what they are, how they interact, and their
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configuration trade-offs.
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Nix has two relevant settings with regards to how your CPU cores will
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be utilized: `cores` and `max-jobs`. This chapter will talk about what
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they are, how they interact, and their configuration trade-offs.
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- [???](#conf-max-jobs)
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- `max-jobs`
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Dictates how many separate derivations will be built at the same
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time. If you set this to zero, the local machine will do no builds.
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Nix will still substitute from binary caches, and build remotely if
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remote builders are configured.
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time. If you set this to zero, the local machine will do no
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builds. Nix will still substitute from binary caches, and build
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remotely if remote builders are configured.
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- [???](#conf-cores)
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Suggests how many cores each derivation should use. Similar to `make
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-j`.
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- `cores`
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Suggests how many cores each derivation should use. Similar to
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`make -j`.
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The [???](#conf-cores) setting determines the value of
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`NIX_BUILD_CORES`. `NIX_BUILD_CORES` is equal to [???](#conf-cores),
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unless [???](#conf-cores) equals `0`, in which case `NIX_BUILD_CORES`
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will be the total number of cores in the system.
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The `cores` setting determines the value of
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`NIX_BUILD_CORES`. `NIX_BUILD_CORES` is equal to `cores`, unless
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`cores` equals `0`, in which case `NIX_BUILD_CORES` will be the total
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number of cores in the system.
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The maximum number of consumed cores is a simple multiplication,
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[???](#conf-max-jobs) \* `NIX_BUILD_CORES`.
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`max-jobs` \* `NIX_BUILD_CORES`.
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The balance on how to set these two independent variables depends upon
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each builder's workload and hardware. Here are a few example scenarios
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on a machine with 24 cores:
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| [???](#conf-max-jobs) | [???](#conf-cores) | `NIX_BUILD_CORES` | Maximum Processes | Result |
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| `max-jobs` | `cores` | `NIX_BUILD_CORES` | Maximum Processes | Result |
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| --------------------- | ------------------ | ----------------- | ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
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| 1 | 24 | 24 | 24 | One derivation will be built at a time, each one can use 24 cores. Undersold if a job can’t use 24 cores. |
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| 4 | 6 | 6 | 24 | Four derivations will be built at once, each given access to six cores. |
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@ -35,8 +34,6 @@ on a machine with 24 cores:
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| 24 | 1 | 1 | 24 | 24 derivations can build at the same time, each using a single core. Never oversold, but derivations which require many cores will be very slow to compile. |
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| 24 | 0 | 24 | 576 | 24 derivations can build at the same time, each using all the available cores of the machine. Very likely to be oversold, and very likely to suffer context switches. |
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Balancing 24 Build Cores
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It is up to the derivations' build script to respect host's requested
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cores-per-build by following the value of the `NIX_BUILD_CORES`
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environment variable.
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@ -1,9 +1,8 @@
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# Verifying Build Reproducibility
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Specify a program with Nix's [???](#conf-diff-hook) to compare build
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results when two builds produce different results. Note: this hook is
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only executed if the results are not the same, this hook is not used for
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determining if the results are the same.
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You can use Nix's `diff-hook` setting to compare build results. Note
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that this hook is only executed if the results differ; it is not used
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for determining if the results are the same.
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For purposes of demonstration, we'll use the following Nix file,
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`deterministic.nix` for testing:
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@ -93,7 +92,7 @@ has copied the build results to that directory where you can examine it.
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> path will be deleted on the next garbage collection.
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>
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> The path is guaranteed to be alive for the duration of
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> [???](#conf-diff-hook)'s execution, but may be deleted any time after.
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> the `diff-hook`'s execution, but may be deleted any time after.
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>
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> If the comparison is performed as part of automated tooling, please
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> use the diff-hook or author your tooling to handle the case where the
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@ -112,9 +111,8 @@ Run the build without `--check`, and then try with `--check` again.
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Automatically verify every build at build time by executing the build
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multiple times.
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Setting [???](#conf-repeat) and [???](#conf-enforce-determinism) in your
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`nix.conf` permits the automated verification of every build Nix
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performs.
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Setting `repeat` and `enforce-determinism` in your `nix.conf` permits
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the automated verification of every build Nix performs.
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The following configuration will run each build three times, and will
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require the build to be deterministic:
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@ -122,9 +120,9 @@ require the build to be deterministic:
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enforce-determinism = true
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repeat = 2
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Setting [???](#conf-enforce-determinism) to false as in the following
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configuration will run the build multiple times, execute the build hook,
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but will allow the build to succeed even if it does not build
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Setting `enforce-determinism` to false as in the following
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configuration will run the build multiple times, execute the build
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hook, but will allow the build to succeed even if it does not build
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reproducibly:
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enforce-determinism = false
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@ -17,9 +17,8 @@ the build loop.
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# Prerequisites
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This tutorial assumes you have configured an S3-compatible binary cache
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according to the instructions at
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[???](#ssec-s3-substituter-authenticated-writes), and that the `root`
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This tutorial assumes you have [configured an S3-compatible binary
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cache](../package-management/s3-substituter.md), and that the `root`
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user's default AWS profile can upload to the bucket.
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# Set up a Signing Key
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@ -33,7 +32,7 @@ distribute the public key for verifying the authenticity of the paths.
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example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM=
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Then, add the public key and the cache URL to your `nix.conf`'s
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[???](#conf-trusted-public-keys) and [???](#conf-substituters) like:
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`trusted-public-keys` and `substituters` options:
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substituters = https://cache.nixos.org/ s3://example-nix-cache
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trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM=
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@ -77,8 +77,7 @@ The following settings are currently available:
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--optimise` to get rid of duplicate files.
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- `builders`
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A list of machines on which to perform builds. See
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[???](#chap-distributed-builds) for details.
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A list of machines on which to perform builds.
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- `builders-use-substitutes`
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If set to `true`, Nix will instruct remote build machines to use
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@ -140,8 +139,6 @@ The following settings are currently available:
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`-jN` flag to GNU Make. It can be overridden using the `--cores`
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command line switch and defaults to `1`. The value `0` means that
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the builder should use all available CPU cores in the system.
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See also [???](#chap-tuning-cores-and-jobs).
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- `diff-hook`
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Absolute path to an executable capable of diffing build results. The
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@ -298,8 +295,6 @@ The following settings are currently available:
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`preferLocalBuild` derivation attribute which executes locally
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regardless). It can be overridden using the `--max-jobs` (`-j`)
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command line switch.
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See also [???](#chap-tuning-cores-and-jobs).
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- `max-silent-time`
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This option defines the maximum number of seconds that a builder can
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@ -429,12 +424,10 @@ The following settings are currently available:
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Example:
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`/nix/store/zf5lbh336mnzf1nlswdn11g4n2m8zh3g-bash-4.4-p23-dev
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/nix/store/rjxwxwv1fpn9wa2x5ssk5phzwlcv4mna-bash-4.4-p23-doc
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/nix/store/6bqvbzjkcp9695dq0dpl5y43nvy37pq1-bash-4.4-p23-info
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/nix/store/r7fng3kk3vlpdlh2idnrbn37vh4imlj2-bash-4.4-p23-man
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/nix/store/xfghy8ixrhz3kyy6p724iv3cxji088dx-bash-4.4-p23`.
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See [???](#chap-post-build-hook) for an example implementation.
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/nix/store/rjxwxwv1fpn9wa2x5ssk5phzwlcv4mna-bash-4.4-p23-doc
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/nix/store/6bqvbzjkcp9695dq0dpl5y43nvy37pq1-bash-4.4-p23-info
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/nix/store/r7fng3kk3vlpdlh2idnrbn37vh4imlj2-bash-4.4-p23-man
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/nix/store/xfghy8ixrhz3kyy6p724iv3cxji088dx-bash-4.4-p23`.
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- `repeat`
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How many times to repeat builds to check whether they are
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@ -459,8 +452,7 @@ The following settings are currently available:
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`allowed-uri`. The default is `false`.
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- `run-diff-hook`
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If true, enable the execution of
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[varlistentry\_title](#conf-diff-hook).
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If true, enable the execution of the `diff-hook` program.
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When using the Nix daemon, `run-diff-hook` must be set in the
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`nix.conf` configuration file, and cannot be passed at the command
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@ -595,15 +587,11 @@ The following settings are currently available:
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Nix will print a log message at the "vomit" level for every function
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entrance and function exit.
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<div class="informalexample">
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function-trace entered undefined position at 1565795816999559622
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function-trace exited undefined position at 1565795816999581277
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function-trace entered /nix/store/.../example.nix:226:41 at 1565795253249935150
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function-trace exited /nix/store/.../example.nix:226:41 at 1565795253249941684
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</div>
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The `undefined position` means the function call is a builtin.
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Use the `contrib/stack-collapse.py` script distributed with the Nix
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@ -46,7 +46,7 @@ expression to a low-level store derivation) and [`nix-store
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All options not listed here are passed to `nix-store
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--realise`, except for `--arg` and `--attr` / `-A` which are passed to
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`nix-instantiate`. See also [???](#sec-common-options).
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`nix-instantiate`.
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- `--no-out-link`
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Do not create a symlink to the output path. Note that as a result
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@ -13,7 +13,6 @@ Title: nix-channel
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A Nix channel is a mechanism that allows you to automatically stay
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up-to-date with a set of pre-built Nix expressions. A Nix channel is
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just a URL that points to a place containing a set of Nix expressions.
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See also [???](#sec-channels).
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To see the list of official NixOS channels, visit
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<https://nixos.org/channels>.
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@ -66,7 +66,7 @@ match. Here are some examples:
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This section lists the options that are common to all operations. These
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options are allowed for every subcommand, though they may not always
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have an effect. See also [???](#sec-common-options).
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have an effect.
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- `--file` / `-f` *path*
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Specifies the Nix expression (designated below as the *active Nix
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@ -30,8 +30,6 @@ the resulting store derivations are printed on standard output.
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If *files* is the character `-`, then a Nix expression will be read from
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standard input.
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See also [???](#sec-common-options) for a list of common options.
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# Options
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- `--add-root` *path*; `--indirect`
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@ -50,7 +50,7 @@ will cause `nix-shell` to print `Hello shell`.
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All options not listed here are passed to `nix-store
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--realise`, except for `--arg` and `--attr` / `-A` which are passed to
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`nix-instantiate`. See also [???](#sec-common-options).
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`nix-instantiate`.
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- `--command` *cmd*
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In the environment of the derivation, run the shell command *cmd*.
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@ -23,16 +23,15 @@ subcommand to be performed. These are documented below.
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This section lists the options that are common to all operations. These
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options are allowed for every subcommand, though they may not always
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have an effect. See also [???](#sec-common-options) for a list of common
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options.
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have an effect.
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- `--add-root` *path*
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Causes the result of a realisation (`--realise` and
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`--force-realise`) to be registered as a root of the garbage
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collector(see [???](#ssec-gc-roots)). The root is stored in *path*,
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which must be inside a directory that is scanned for roots by the
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garbage collector (i.e., typically in a subdirectory of
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`/nix/var/nix/gcroots/`) *unless* the `--indirect` flag is used.
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collector. The root is stored in *path*, which must be inside a
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directory that is scanned for roots by the garbage collector
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(i.e., typically in a subdirectory of `/nix/var/nix/gcroots/`)
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*unless* the `--indirect` flag is used.
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If there are multiple results, then multiple symlinks will be
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created by sequentially numbering symlinks beyond the first one
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@ -209,8 +208,7 @@ The following suboperations may be specified:
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- `--print-roots`
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This operation prints on standard output the set of roots used by
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the garbage collector. What constitutes a root is described in
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[???](#ssec-gc-roots).
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the garbage collector.
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- `--print-live`
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This operation prints on standard output the set of “live” store
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@ -1,11 +1,12 @@
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# Arguments and Variables
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The Nix expression in [???](#ex-hello-nix) is a function; it is missing
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some arguments that have to be filled in somewhere. In the Nix Packages
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collection this is done in the file `pkgs/top-level/all-packages.nix`,
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where all Nix expressions for packages are imported and called with the
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appropriate arguments. Here are some fragments of `all-packages.nix`,
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with annotations of what they mean:
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The [Nix expression for GNU Hello](expression-syntax.md) is a
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function; it is missing some arguments that have to be filled in
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somewhere. In the Nix Packages collection this is done in the file
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`pkgs/top-level/all-packages.nix`, where all Nix expressions for
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packages are imported and called with the appropriate arguments. Here
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are some fragments of `all-packages.nix`, with annotations of what
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they mean:
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...
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@ -35,9 +36,10 @@ with annotations of what they mean:
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2. Here we *import* the Nix expression for GNU Hello. The import
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operation just loads and returns the specified Nix expression. In
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fact, we could just have put the contents of [???](#ex-hello-nix) in
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`all-packages.nix` at this point. That would be completely
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equivalent, but it would make the file rather bulky.
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fact, we could just have put the contents of the Nix expression
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for GNU Hello in `all-packages.nix` at this point. That would be
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completely equivalent, but it would make `all-packages.nix` rather
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bulky.
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Note that we refer to `../applications/misc/hello/ex-1`, not
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`../applications/misc/hello/ex-1/default.nix`. When you try to
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@ -54,7 +56,7 @@ with annotations of what they mean:
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The result of this function call is an actual derivation that can be
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built by Nix (since when we fill in the arguments of the function,
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what we get is its body, which is the call to `stdenv.mkDerivation`
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in [???](#ex-hello-nix)).
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in the [Nix expression for GNU Hello](expression-syntax.md)).
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> **Note**
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>
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@ -25,10 +25,10 @@ steps to elucidate what a builder does. It performs the following steps:
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So the first step is to set up the environment. This is done by
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calling the `setup` script of the standard environment. The
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environment variable `stdenv` points to the location of the standard
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environment being used. (It wasn't specified explicitly as an
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attribute in [???](#ex-hello-nix), but `mkDerivation` adds it
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automatically.)
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environment variable `stdenv` points to the location of the
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standard environment being used. (It wasn't specified explicitly
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as an attribute in Hello's Nix expression, but `mkDerivation` adds
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it automatically.)
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2. Since Hello needs Perl, we have to make sure that Perl is in the
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`PATH`. The `perl` environment variable points to the location of
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|
@ -1,72 +0,0 @@
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# Builder Syntax
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source $stdenv/setup
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PATH=$perl/bin:$PATH
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tar xvfz $src
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cd hello-*
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./configure --prefix=$out
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make
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make install
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[example\_title](#ex-hello-builder) shows the builder referenced from
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Hello's Nix expression (stored in
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`pkgs/applications/misc/hello/ex-1/builder.sh`). The builder can
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actually be made a lot shorter by using the *generic builder* functions
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||||
provided by `stdenv`, but here we write out the build steps to elucidate
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||||
what a builder does. It performs the following steps:
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- When Nix runs a builder, it initially completely clears the
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environment (except for the attributes declared in the derivation).
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For instance, the `PATH` variable is empty\[1\]. This is done to
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prevent undeclared inputs from being used in the build process. If
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for example the `PATH` contained `/usr/bin`, then you might
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accidentally use `/usr/bin/gcc`.
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So the first step is to set up the environment. This is done by
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calling the `setup` script of the standard environment. The
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environment variable `stdenv` points to the location of the standard
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environment being used. (It wasn't specified explicitly as an
|
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attribute in [???](#ex-hello-nix), but `mkDerivation` adds it
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automatically.)
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|
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- Since Hello needs Perl, we have to make sure that Perl is in the
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`PATH`. The `perl` environment variable points to the location of
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the Perl package (since it was passed in as an attribute to the
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derivation), so `$perl/bin` is the directory containing the Perl
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interpreter.
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- Now we have to unpack the sources. The `src` attribute was bound to
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the result of fetching the Hello source tarball from the network, so
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||||
the `src` environment variable points to the location in the Nix
|
||||
store to which the tarball was downloaded. After unpacking, we `cd`
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to the resulting source directory.
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The whole build is performed in a temporary directory created in
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`/tmp`, by the way. This directory is removed after the builder
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finishes, so there is no need to clean up the sources afterwards.
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Also, the temporary directory is always newly created, so you don't
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have to worry about files from previous builds interfering with the
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current build.
|
||||
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||||
- GNU Hello is a typical Autoconf-based package, so we first have to
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run its `configure` script. In Nix every package is stored in a
|
||||
separate location in the Nix store, for instance
|
||||
`/nix/store/9a54ba97fb71b65fda531012d0443ce2-hello-2.1.1`. Nix
|
||||
computes this path by cryptographically hashing all attributes of
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the derivation. The path is passed to the builder through the `out`
|
||||
environment variable. So here we give `configure` the parameter
|
||||
`--prefix=$out` to cause Hello to be installed in the expected
|
||||
location.
|
||||
|
||||
- Finally we build Hello (`make`) and install it into the location
|
||||
specified by `out` (`make install`).
|
||||
|
||||
If you are wondering about the absence of error checking on the result
|
||||
of various commands called in the builder: this is because the shell
|
||||
script is evaluated with Bash's `-e` option, which causes the script to
|
||||
be aborted if any command fails without an error check.
|
||||
|
||||
1. Actually, it's initialised to `/path-not-set` to prevent Bash from
|
||||
setting it to a default value.
|
@ -83,7 +83,7 @@ For instance, `derivation` is also available as `builtins.derivation`.
|
||||
its elements or attributes are also evaluated recursively.
|
||||
|
||||
- `derivation` *attrs*; `builtins.derivation` *attrs*
|
||||
`derivation` is described in [???](#ssec-derivation).
|
||||
`derivation` is described in [its own section](derivations.md).
|
||||
|
||||
- `dirOf` *s*; `builtins.dirOf` *s*
|
||||
Return the directory part of the string *s*, that is, everything
|
||||
@ -233,8 +233,8 @@ For instance, `derivation` is also available as `builtins.derivation`.
|
||||
|
||||
> **Note**
|
||||
>
|
||||
> Nix will refetch the branch in accordance to
|
||||
> [???](#conf-tarball-ttl).
|
||||
> Nix will refetch the branch in accordance with
|
||||
> the option `tarball-ttl`.
|
||||
|
||||
> **Note**
|
||||
>
|
||||
@ -351,19 +351,18 @@ For instance, `derivation` is also available as `builtins.derivation`.
|
||||
|
||||
- `import` *path*; `builtins.import` *path*
|
||||
Load, parse and return the Nix expression in the file *path*. If
|
||||
*path* is a directory, the file ` default.nix
|
||||
` in that directory is loaded. Evaluation aborts if the file
|
||||
doesn’t exist or contains an incorrect Nix expression. `import`
|
||||
implements Nix’s module system: you can put any Nix expression (such
|
||||
as a set or a function) in a separate file, and use it from Nix
|
||||
expressions in other files.
|
||||
*path* is a directory, the file ` default.nix ` in that directory
|
||||
is loaded. Evaluation aborts if the file doesn’t exist or contains
|
||||
an incorrect Nix expression. `import` implements Nix’s module
|
||||
system: you can put any Nix expression (such as a set or a
|
||||
function) in a separate file, and use it from Nix expressions in
|
||||
other files.
|
||||
|
||||
> **Note**
|
||||
>
|
||||
> Unlike some languages, `import` is a regular function in Nix.
|
||||
> Paths using the angle bracket syntax (e.g., `
|
||||
> > > > > import` *\<foo\>*) are normal path values (see
|
||||
> [???](#ssec-values)).
|
||||
> Paths using the angle bracket syntax (e.g., `import` *\<foo\>*)
|
||||
> are [normal path values](language-values.md).
|
||||
|
||||
A Nix expression loaded by `import` must not contain any *free
|
||||
variables* (identifiers that are not defined in the Nix expression
|
||||
@ -643,11 +642,12 @@ For instance, `derivation` is also available as `builtins.derivation`.
|
||||
(which is not the case for `abort`).
|
||||
|
||||
- `builtins.toFile` *name* *s*
|
||||
Store the string *s* in a file in the Nix store and return its path.
|
||||
The file has suffix *name*. This file can be used as an input to
|
||||
derivations. One application is to write builders “inline”. For
|
||||
instance, the following Nix expression combines [???](#ex-hello-nix)
|
||||
and [???](#ex-hello-builder) into one file:
|
||||
Store the string *s* in a file in the Nix store and return its
|
||||
path. The file has suffix *name*. This file can be used as an
|
||||
input to derivations. One application is to write builders
|
||||
“inline”. For instance, the following Nix expression combines the
|
||||
[Nix expression for GNU Hello](expression-syntax.md) and its
|
||||
[build script](build-script.md) into one file:
|
||||
|
||||
{ stdenv, fetchurl, perl }:
|
||||
|
||||
@ -688,8 +688,9 @@ For instance, `derivation` is also available as `builtins.derivation`.
|
||||
";
|
||||
```
|
||||
|
||||
Note that `${configFile}` is an antiquotation (see
|
||||
[???](#ssec-values)), so the result of the expression `configFile`
|
||||
Note that `${configFile}` is an
|
||||
[antiquotation](language-values.md), so the result of the
|
||||
expression `configFile`
|
||||
(i.e., a path like `/nix/store/m7p7jfny445k...-foo.conf`) will be
|
||||
spliced into the resulting string.
|
||||
|
||||
@ -786,17 +787,17 @@ For instance, `derivation` is also available as `builtins.derivation`.
|
||||
container contains a number of servlets (`*.war` files) each
|
||||
exported under a specific URI prefix. So the servlet configuration
|
||||
is a list of sets containing the `path` and `war` of the servlet
|
||||
([???](#ex-toxml-co-servlets)). This kind of information is
|
||||
difficult to communicate with the normal method of passing
|
||||
information through an environment variable, which just concatenates
|
||||
everything together into a string (which might just work in this
|
||||
case, but wouldn’t work if fields are optional or contain lists
|
||||
themselves). Instead the Nix expression is converted to an XML
|
||||
representation with `toXML`, which is unambiguous and can easily be
|
||||
processed with the appropriate tools. For instance, in the example
|
||||
an XSLT stylesheet (at point ②) is applied to it (at point ①) to
|
||||
generate the XML configuration file for the Jetty server. The XML
|
||||
representation produced at point ③ by `toXML` is as follows:
|
||||
(①). This kind of information is difficult to communicate with the
|
||||
normal method of passing information through an environment
|
||||
variable, which just concatenates everything together into a
|
||||
string (which might just work in this case, but wouldn’t work if
|
||||
fields are optional or contain lists themselves). Instead the Nix
|
||||
expression is converted to an XML representation with `toXML`,
|
||||
which is unambiguous and can easily be processed with the
|
||||
appropriate tools. For instance, in the example an XSLT stylesheet
|
||||
(at point ②) is applied to it (at point ①) to generate the XML
|
||||
configuration file for the Jetty server. The XML representation
|
||||
produced at point ③ by `toXML` is as follows:
|
||||
|
||||
<?xml version='1.0' encoding='utf-8'?>
|
||||
<expr>
|
||||
@ -820,10 +821,10 @@ For instance, `derivation` is also available as `builtins.derivation`.
|
||||
</list>
|
||||
</expr>
|
||||
|
||||
Note that [???](#ex-toxml) uses the `toFile` built-in to write the
|
||||
builder and the stylesheet “inline” in the Nix expression. The path
|
||||
of the stylesheet is spliced into the builder using the syntax
|
||||
`xsltproc ${stylesheet}`.
|
||||
Note that we used the `toFile` built-in to write the builder and
|
||||
the stylesheet “inline” in the Nix expression. The path of the
|
||||
stylesheet is spliced into the builder using the syntax `xsltproc
|
||||
${stylesheet}`.
|
||||
|
||||
- `builtins.trace` *e1* *e2*
|
||||
Evaluate *e1* and print its abstract syntax representation on
|
||||
|
@ -9,8 +9,9 @@ the attributes of which specify the inputs of the build.
|
||||
`"x86_64-darwin"`. (To figure out your system type, run `nix -vv
|
||||
--version`.) The build can only be performed on a machine and
|
||||
operating system matching the system type. (Nix can automatically
|
||||
forward builds for other platforms by forwarding them to other
|
||||
machines; see [???](#chap-distributed-builds).)
|
||||
[forward builds for other
|
||||
platforms](../advanced-topics/distributed-builds.md) by forwarding
|
||||
them to other machines.)
|
||||
|
||||
- There must be an attribute named `name` whose value must be a
|
||||
string. This is used as a symbolic name for the package by
|
||||
|
@ -61,9 +61,10 @@ elements (referenced from the figure by number):
|
||||
sometimes be omitted, in which case `mkDerivation` will fill in a
|
||||
default builder (which does a `configure; make; make install`, in
|
||||
essence). Hello is sufficiently simple that the default builder
|
||||
would suffice, but in this case, we will show an actual builder for
|
||||
educational purposes. The value `./builder.sh` refers to the shell
|
||||
script shown in [???](#ex-hello-builder), discussed below.
|
||||
would suffice, but in this case, we will show an actual builder
|
||||
for educational purposes. The value `./builder.sh` refers to the
|
||||
shell script shown in the [next section](build-script.md),
|
||||
discussed below.
|
||||
|
||||
5. The builder has to know what the sources of the package are. Here,
|
||||
the attribute `src` is bound to the result of a call to the
|
||||
|
@ -1,7 +1,7 @@
|
||||
# Generic Builder Syntax
|
||||
|
||||
Recall from [???](#ex-hello-builder) that the builder looked something
|
||||
like this:
|
||||
Recall that the [build script for GNU Hello](build-script.md) looked
|
||||
something like this:
|
||||
|
||||
PATH=$perl/bin:$PATH
|
||||
tar xvfz $src
|
||||
@ -37,11 +37,10 @@ Here is what each line means:
|
||||
2. The function `genericBuild` is defined in the file `$stdenv/setup`.
|
||||
|
||||
3. The final step calls the shell function `genericBuild`, which
|
||||
performs the steps that were done explicitly in
|
||||
[???](#ex-hello-builder). The generic builder is smart enough to
|
||||
figure out whether to unpack the sources using `gzip`, `bzip2`, etc.
|
||||
It can be customised in many ways; see the Nixpkgs manual for
|
||||
details.
|
||||
performs the steps that were done explicitly in the previous build
|
||||
script. The generic builder is smart enough to figure out whether
|
||||
to unpack the sources using `gzip`, `bzip2`, etc. It can be
|
||||
customised in many ways; see the Nixpkgs manual for details.
|
||||
|
||||
Discerning readers will note that the `buildInputs` could just as well
|
||||
have been set in the Nix expression, like this:
|
||||
|
@ -1,8 +1,7 @@
|
||||
# Operators
|
||||
|
||||
[table\_title](#table-operators) lists the operators in the Nix
|
||||
expression language, in order of precedence (from strongest to weakest
|
||||
binding).
|
||||
The table below lists the operators in the Nix expression language, in
|
||||
order of precedence (from strongest to weakest binding).
|
||||
|
||||
| Name | Syntax | Associativity | Description | Precedence |
|
||||
| ------------------------ | ----------------------------------- | ------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------- |
|
||||
@ -28,5 +27,3 @@ binding).
|
||||
| Logical OR | *e1* `\|\|` *e2* | left | Logical OR. | 13 |
|
||||
| Logical Implication | *e1* `->` *e2* | none | Logical implication (equivalent to `!e1 \|\|
|
||||
e2`). | 14 |
|
||||
|
||||
Operators
|
||||
|
@ -3,7 +3,7 @@
|
||||
- derivation
|
||||
A description of a build action. The result of a derivation is a
|
||||
store object. Derivations are typically specified in Nix expressions
|
||||
using the [`derivation` primitive](#ssec-derivation). These are
|
||||
using the [`derivation` primitive](expressions/derivations.md). These are
|
||||
translated into low-level *store derivations* (implicitly by
|
||||
`nix-env` and `nix-build`, or explicitly by `nix-instantiate`).
|
||||
|
||||
@ -53,20 +53,19 @@
|
||||
paths.
|
||||
|
||||
- reachable
|
||||
A store path `Q` is reachable from another store path `P` if `Q` is
|
||||
in the [closure](#gloss-closure) of the
|
||||
[references](#gloss-reference) relation.
|
||||
A store path `Q` is reachable from another store path `P` if `Q`
|
||||
is in the *closure* of the *references* relation.
|
||||
|
||||
- closure
|
||||
The closure of a store path is the set of store paths that are
|
||||
directly or indirectly “reachable” from that store path; that is,
|
||||
it’s the closure of the path under the
|
||||
[references](#gloss-reference) relation. For a package, the closure
|
||||
of its derivation is equivalent to the build-time dependencies,
|
||||
while the closure of its output path is equivalent to its runtime
|
||||
dependencies. For correct deployment it is necessary to deploy whole
|
||||
closures, since otherwise at runtime files could be missing. The
|
||||
command `nix-store -qR` prints out closures of store paths.
|
||||
it’s the closure of the path under the *references* relation. For
|
||||
a package, the closure of its derivation is equivalent to the
|
||||
build-time dependencies, while the closure of its output path is
|
||||
equivalent to its runtime dependencies. For correct deployment it
|
||||
is necessary to deploy whole closures, since otherwise at runtime
|
||||
files could be missing. The command `nix-store -qR` prints out
|
||||
closures of store paths.
|
||||
|
||||
As an example, if the store object at path `P` contains a reference
|
||||
to path `Q`, then `Q` is in the closure of `P`. Further, if `Q`
|
||||
@ -76,7 +75,7 @@
|
||||
A store path produced by a derivation.
|
||||
|
||||
- deriver
|
||||
The deriver of an [output path](#gloss-output-path) is the store
|
||||
The deriver of an *output path* is the store
|
||||
derivation that built it.
|
||||
|
||||
- validity
|
||||
@ -87,16 +86,15 @@
|
||||
- user environment
|
||||
An automatically generated store object that consists of a set of
|
||||
symlinks to “active” applications, i.e., other store paths. These
|
||||
are generated automatically by [`nix-env`](#sec-nix-env). See
|
||||
[???](#sec-profiles).
|
||||
are generated automatically by
|
||||
[`nix-env`](command-ref/nix-env.md). See *profiles*.
|
||||
|
||||
- profile
|
||||
A symlink to the current [user environment](#gloss-user-env) of a
|
||||
user, e.g., `/nix/var/nix/profiles/default`.
|
||||
A symlink to the current *user environment* of a user, e.g.,
|
||||
`/nix/var/nix/profiles/default`.
|
||||
|
||||
- NAR
|
||||
A *N*ix *AR*chive. This is a serialisation of a path in the Nix
|
||||
store. It can contain regular files, directories and symbolic links.
|
||||
NARs are generated and unpacked using `nix-store --dump` and
|
||||
`nix-store
|
||||
--restore`.
|
||||
store. It can contain regular files, directories and symbolic
|
||||
links. NARs are generated and unpacked using `nix-store --dump`
|
||||
and `nix-store --restore`.
|
||||
|
@ -24,11 +24,11 @@ or completely new ones.)
|
||||
|
||||
You can manually download the latest version of Nixpkgs from
|
||||
<http://nixos.org/nixpkgs/download.html>. However, it’s much more
|
||||
convenient to use the Nixpkgs *channel*, since it makes it easy to stay
|
||||
up to date with new versions of Nixpkgs. (Channels are described in more
|
||||
detail in [???](#sec-channels).) Nixpkgs is automatically added to your
|
||||
list of “subscribed” channels when you install Nix. If this is not the
|
||||
case for some reason, you can add it as follows:
|
||||
convenient to use the Nixpkgs [*channel*](channels.md), since it makes
|
||||
it easy to stay up to date with new versions of Nixpkgs. Nixpkgs is
|
||||
automatically added to your list of “subscribed” channels when you
|
||||
install Nix. If this is not the case for some reason, you can add it
|
||||
as follows:
|
||||
|
||||
$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable
|
||||
$ nix-channel --update
|
||||
|
@ -8,7 +8,7 @@ dependencies:
|
||||
|
||||
$ nix-copy-closure --to alice@itchy.example.org $(type -p firefox)
|
||||
|
||||
See [???](#sec-nix-copy-closure) for details.
|
||||
See the [manpage for `nix-copy-closure`](../command-ref/nix-copy-closure.md) for details.
|
||||
|
||||
With `nix-store
|
||||
--export` and `nix-store --import` you can write the closure of a store
|
||||
|
@ -1,4 +1,5 @@
|
||||
This chapter discusses how to do package management with Nix, i.e., how
|
||||
to obtain, install, upgrade, and erase packages. This is the “user’s”
|
||||
perspective of the Nix system — people who want to *create* packages
|
||||
should consult [???](#chap-writing-nix-expressions).
|
||||
This chapter discusses how to do package management with Nix, i.e.,
|
||||
how to obtain, install, upgrade, and erase packages. This is the
|
||||
“user’s” perspective of the Nix system — people who want to *create*
|
||||
packages should consult the [chapter on writing Nix
|
||||
expressions](../expressions/writing-nix-expressions.md).
|
||||
|
@ -104,8 +104,7 @@ These commands switch to the `my-profile` and default profile,
|
||||
respectively. If the profile doesn’t exist, it will be created
|
||||
automatically. You should be careful about storing a profile in another
|
||||
location than the `profiles` directory, since otherwise it might not be
|
||||
used as a root of the garbage collector (see
|
||||
[???](#sec-garbage-collection)).
|
||||
used as a root of the [garbage collector](garbage-collection.md).
|
||||
|
||||
All `nix-env` operations work on the profile pointed to by
|
||||
`~/.nix-profile`, but you can override this using the `--profile` option
|
||||
|
Loading…
Reference in New Issue
Block a user