crane/docs/API.md

API Documentation

mkLib

mkLib :: pkgs -> set

Creates a lib instance bound to the specified (and instantiated) pkgs set. This is a convenience escape hatch in case you want to use your own custom instantiation of nixpkgs with the overlays you may need.

mkLib (import inputs.nixpkgs { system = "armv7l-linux"; })

Note that if you wish to override a particular package without having to overlay it across all of nixpkgs, consider using overrideScope':

(mkLib pkgs).overrideScope' (final: prev: {
  cargo-tarpaulin = myCustomCargoTarpaulinVersion;
})

To overlay an entire rust toolchain (e.g. cargo, rustc, clippy, rustfmt, etc.) consider using overrideToolchain.

lib

lib.appendCrateRegistries

appendCrateRegistries :: [registry mapping] -> new lib

Creates a new lib instance which will make additional registries available for use when downloading crate sources. Each entry can be defined using:

• registryFromDownloadUrl: if you know the exact dl URL as defined in the registry's config.json file
• registryFromGitIndex: if you would like the download URL to be inferred from the index's source directly.

See the documentation on each function for more specifics.

newLib = lib.appendCrateRegistries [
  (lib.registryFromDownloadUrl {
    indexUrl = "https://github.com/rust-lang/crates.io-index";
    dl = "https://crates.io/api/v1/crates";
  })

  # Or, alternatively
  (lib.registryFromGitIndex {
    indexUrl = "https://github.com/Hirevo/alexandrie-index";
    rev = "90df25daf291d402d1ded8c32c23d5e1498c6725";
  })
];

lib.buildDepsOnly

buildDepsOnly :: set -> drv

Create a derivation which will only build all dependencies of a cargo workspace.

Useful for splitting up cargo projects into two derivations: one which only builds dependencies and needs to be rebuilt when a Cargo.lock file changes, and another which inherits the cargo artifacts from the first and (quickly) builds just the application itself.

The exact cargo commands being run (or the arguments passed into it) can be easily updated to suit your needs. By default all artifacts from running cargo {check,build,test} will be cached.

In addition to all default and overridden values being set as documented below, all derivation attributes are delegated to mkCargoDerivation, and can be used to influence its behavior.

• cargoArtifacts: set to null since this is our entry point for generating cargo artifacts
• doInstallCargoArtifacts: set to true
• pnameSuffix: set to "-deps"
• src: set to the result of mkDummySrc after applying the arguments set. This ensures that we do not need to rebuild the cargo artifacts derivation whenever the application source changes.

Optional attributes

• buildPhaseCargoCommand: A command to run during the derivation's build phase. Pre and post build hooks will automatically be run.
  • Default value: "${cargoCheckCommand} ${cargoExtraArgs}\n${cargoBuildCommand} ${cargoExtraArgs}"
• cargoBuildCommand: A cargo (build) invocation to run during the derivation's build phase
  • Default value: "cargo build --profile release"
    • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• cargoCheckCommand: A cargo (check) invocation to run during the derivation's build phase (in order to cache additional artifacts)
  • Default value: "cargo check --profile release --all-targets"
    • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• cargoExtraArgs: additional flags to be passed in the cargo invocation (e.g. enabling specific features)
• cargoTestCommand: A cargo invocation to run during the derivation's check phase
  • Default value: "cargo test --profile release"
    • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• cargoVendorDir: A path (or derivation) of vendored cargo sources which can be consumed without network access. Directory structure should basically follow the output of cargo vendor.
  • Default value: the result of vendorCargoDeps after applying the arguments set (with the respective default values)
• checkPhaseCargoCommand: A command to run during the derivation's check phase. Pre and post check hooks will automatically be run.
  • Default value: "${cargoTestCommand} ${cargoExtraArgs}"
• doCheck: whether the derivation's check phase should be run
  • Default value: true
• dummySrc: the "dummy" source to use when building this derivation. Automatically derived if not passed in
  • Default value: mkDummySrc args.src
• pname: package name of the derivation
  • Default value: inherited from calling crateNameFromCargoToml
• version: version of the derivation
  • Default value: inherited from calling crateNameFromCargoToml

Remove attributes

The following attributes will be removed before being lowered to mkCargoDerivation. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• cargoBuildCommand
• cargoCheckCommand
• cargoExtraArgs
• cargoTestCommand
• dummySrc

lib.buildPackage

buildPackage :: set -> drv

A(n opinionated) version of cargoBuild which will install to the output any binaries which were built by cargo in this invocation. All options understood by cargoBuild apply here as well, with the only difference being some additional book keeping necessary to log cargo's results and subsequently install from that log.

Optional attributes

• buildPhase: the commands used by the build phase of the derivation
  • Default value: the build phase will run preBuild hooks, print the cargo version, log and evaluate buildPhaseCargoCommand, and run postBuild hooks
• buildPhaseCargoCommand: A command to run during the derivation's build phase. Pre and post build hooks will automatically be run.
  • Default value: cargoBuildCommand will be invoked along with cargoExtraArgs passed in, except cargo's build steps will also be captured and written to a log so that it can be used to find the build binaries.
  • Note that the default install hook assumes that the build phase will create a log of cargo's build results. If you wish to customize this command completely, make sure that cargo is run with --message-format json-render-diagnostics and the standard output captured and saved to a file. The cargoBuildLog shell variable should point to this log.
• cargoBuildCommand: A cargo invocation to run during the derivation's build phase
  • Default value: "cargo build --profile release"
    • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• cargoExtraArgs: additional flags to be passed in the cargo invocation (e.g. enabling specific features)
  • Default value: ""
• doInstallCargoArtifacts: controls whether cargo's target directory should be copied as an output
  • Default value: false
• installPhase: the commands used by the install phase of the derivation
  • Default value: the install phase will run preInstall hooks, look for a cargo build log and install all binary targets listed there, and run postInstall hooks

Native build dependencies and included hooks

The following hooks are automatically added as native build inputs:

• installFromCargoBuildLogHook
• jq
• removeReferencesTo
• removeReferencesToVendoredSourcesHook

lib.cargoAudit

cargoAudit :: set -> drv

Create a derivation which will run a cargo audit invocation in a cargo workspace.

Except where noted below, all derivation attributes are delegated to mkCargoDerivation, and can be used to influence its behavior.

• buildPhaseCargoCommand will be set to run cargo audit -n -d ${advisory-db} in the workspace.
• cargoArtifacts will be set to null as they are not needed
• cargoVendorDir will be set to null as it is not needed
• doInstallCargoArtifacts is disabled
• pnameSuffix will be set to "-audit"
• src will be filtered to only keep Cargo.lock files

Required attributes

• advisory-db: A path (or derivation) which contains the advisory database
  • It is possible to track the advisory database as a flake input and avoid having to manually update hashes or specific revisions to check out
• src: The project source to audit, it must contain a Cargo.lock file
  • Note that the source will internally be filtered to omit any files besides Cargo.lock. This avoids having to audit the project again until either the advisory database or the dependencies change.

Optional attributes

• cargoAuditExtraArgs: additional flags to be passed in the cargo-audit invocation
  • Default value: ""
• cargoExtraArgs: additional flags to be passed in the cargo invocation
  • Default value: ""
• pname: the name of the derivation; will not be introspected from a Cargo.toml file
  • Default value: "crate"
• version: the version of the derivation, will not be introspected from a Cargo.toml file
  • Default value: "0.0.0"

Native build dependencies

The cargo-audit package is automatically appended as a native build input to any other nativeBuildInputs specified by the caller.

Remove attributes

The following attributes will be removed before being lowered to cargoBuild. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• cargoAuditExtraArgs
• cargoExtraArgs

lib.cargoBuild

cargoBuild :: set -> drv

Create a derivation which will build and test a cargo workspace.

The exact cargo command being run (or the arguments passed into it) can be easily updated to suit your needs. If a project requires multiple cargo invocations, they can either be run one after the other (as you'd expect in a regular derivation), or they can be split out into separate derivations and chained together via cargoArtifacts which would allow for more incremental building and caching of the results.

Consider using buildPackage if all you need is to build the workspace and install the resulting application binaries.

In addition to all default values being set as documented below, all derivation attributes are delegated to mkCargoDerivation, and can be used to influence its behavior.

Optional attributes

• buildPhaseCargoCommand: A command to run during the derivation's build phase. Pre and post build hooks will automatically be run.
  • Default value: "${cargoBuildCommand} ${cargoExtraArgs}"
• cargoArtifacts: A path (or derivation) which contains an existing cargo target directory, which will be reused at the start of the derivation. Useful for caching incremental cargo builds.
  • Default value: the result of buildDepsOnly after applying the arguments set (with the respective default values)
• cargoBuildCommand: A cargo invocation to run during the derivation's build phase
  • Default value: "cargo build --profile release"
    • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• cargoExtraArgs: additional flags to be passed in the cargo invocation (e.g. enabling specific features)
  • Default value: ""
• cargoTestCommand: A cargo invocation to run during the derivation's check phase
  • Default value: "cargo test --profile release"
    • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• cargoVendorDir: A path (or derivation) of vendored cargo sources which can be consumed without network access. Directory structure should basically follow the output of cargo vendor.
  • Default value: the result of vendorCargoDeps after applying the arguments set (with the respective default values)
• checkPhaseCargoCommand: A command to run during the derivation's check phase. Pre and post check hooks will automatically be run.
  • Default value: "${cargoTestCommand} ${cargoExtraArgs}"
• doCheck: whether the derivation's check phase should be run
  • Default value: true
• doInstallCargoArtifacts: controls whether cargo's target directory should be copied as an output
  • Default value: true
• pname: package name of the derivation
  • Default value: inherited from calling crateNameFromCargoToml
• version: version of the derivation
  • Default value: inherited from calling crateNameFromCargoToml

Remove attributes

The following attributes will be removed before being lowered to mkCargoDerivation. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• cargoBuildCommand
• cargoExtraArgs
• cargoTestCommand

lib.cargoClippy

cargoClippy :: set -> drv

Create a derivation which will run a cargo clippy invocation in a cargo workspace.

Except where noted below, all derivation attributes are delegated to cargoBuild, and can be used to influence its behavior.

• cargoBuildCommand will be set to run cargo clippy --profile release for the workspace.
  • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• cargoExtraArgs will have cargoClippyExtraArgs appended to it
  • Default value: "--all-targets"
• doCheck is disabled
• pnameSuffix will be set to "-clippy"

Required attributes

• cargoArtifacts: A path (or derivation) which contains an existing cargo target directory, which will be reused at the start of the derivation. Useful for caching incremental cargo builds.
  • This can be prepared via buildDepsOnly
  • Alternatively, any cargo-based derivation which was built with doInstallCargoArtifacts = true will work as well

Optional attributes

• cargoClippyExtraArgs: additional flags to be passed in the clippy invocation (e.g. deny specific lints)
  • Default value: "--all-targets"
• cargoExtraArgs: additional flags to be passed in the cargo invocation (e.g. enabling specific features)
  • Default value: ""

Native build dependencies

The clippy package is automatically appended as a native build input to any other nativeBuildInputs specified by the caller.

Remove attributes

The following attributes will be removed before being lowered to cargoBuild. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• cargoClippyExtraArgs

lib.cargoDoc

cargoDoc :: set -> drv

Create a derivation which will run a cargo doc invocation in a cargo workspace.

Except where noted below, all derivation attributes are delegated to mkCargoDerivation, and can be used to influence its behavior.

• buildPhaseCargoCommand will be set to run cargo doc --profile release for the workspace.
  • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• pnameSuffix will be set to "-doc"

Required attributes

• cargoArtifacts: A path (or derivation) which contains an existing cargo target directory, which will be reused at the start of the derivation. Useful for caching incremental cargo builds.
  • This can be prepared via buildDepsOnly
  • Alternatively, any cargo-based derivation which was built with doInstallCargoArtifacts = true will work as well

Optional attributes

• cargoDocExtraArgs: additional flags to be passed in the rustdoc invocation (e.g. deny specific lints)
  • Default value: "--no-deps"
• cargoExtraArgs: additional flags to be passed in the cargo invocation (e.g. enabling specific features)
  • Default value: ""

Remove attributes

The following attributes will be removed before being lowered to cargoBuild. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• cargoDocExtraArgs
• cargoExtraArgs

lib.cargoFmt

cargoFmt :: set -> drv

Create a derivation which will run a cargo fmt invocation in a cargo workspace.

Except where noted below, all derivation attributes are delegated to mkCargoDerivation, and can be used to influence its behavior.

• buildPhaseCargoCommand will be set to run cargo fmt (in check mode) in the workspace.
• cargoArtifacts is disabled/cleared
• cargoVendorDir is disabled/cleared
• pnameSuffix will be set to "-fmt"

Optional attributes

• cargoExtraArgs: additional flags to be passed in the cargo invocation
  • Default value: ""
• rustFmtExtraArgs: additional flags to be passed in the rustfmt invocation
  • Default value: ""

Native build dependencies

The rustfmt package is automatically appended as a native build input to any other nativeBuildInputs specified by the caller.

Remove attributes

The following attributes will be removed before being lowered to cargoBuild. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• cargoExtraArgs
• rustFmtExtraArgs

lib.cargoNextest

cargoNextest :: set -> drv

Create a derivation which will run a cargo nextest invocation in a cargo workspace.

Except where noted below, all derivation attributes are delegated to cargoBuild, and can be used to influence its behavior.

• cargoTestCommand will be set to run cargo nextest run --profile release for the workspace.
  • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• cargoExtraArgs will have cargoNextestExtraArgs appended to it, along with any additional flags needed for handling multiple partitions
  • Default value: ""
• pnameSuffix will be set to "-nextest" and may include partition numbers

Required attributes

• cargoArtifacts: A path (or derivation) which contains an existing cargo target directory, which will be reused at the start of the derivation. Useful for caching incremental cargo builds.
  • This can be prepared via buildDepsOnly
  • Alternatively, any cargo-based derivation which was built with doInstallCargoArtifacts = true will work as well

Optional attributes

• buildPhaseCargoCommand, unless specified, will be set to print the nextest version
• cargoExtraArgs: additional flags to be passed in the cargo invocation (e.g. enabling specific features)
  • Default value: ""
• cargoNextestExtraArgs: additional flags to be passed in the clippy invocation (e.g. deny specific lints)
  • Default value: ""
• partitions: The number of separate nextest partitions to run. Useful if the test suite takes a long time and can be parallelized across multiple build nodes.
  • Default value: 1
• partitionType: The kind of nextest partition to run (e.g. "count" or "hash" based).
  • Default value: "count"

Native build dependencies

The cargo-nextest package is automatically appended as a native build input to any other nativeBuildInputs specified by the caller.

Remove attributes

The following attributes will be removed before being lowered to cargoBuild. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• cargoNextestExtraArgs
• partitions
• partitionType

lib.cargoTarpaulin

cargoTarpaulin :: set -> drv

Create a derivation which will run a cargo tarpaulin invocation in a cargo workspace.

Except where noted below, all derivation attributes are delegated to mkCargoDerivation, and can be used to influence its behavior.

• cargoArtifacts will be instantiated via buildDepsOnly if not specified
  • cargoTarpaulinExtraArgs will be removed before delegating to buildDepsOnly
• buildPhaseCargoCommand will be set to run cargo tarpaulin --profile release in the workspace.
  • CARGO_PROFILE can be set on the derivation to alter which cargo profile is selected; setting it to "" will omit specifying a profile altogether.
• pnameSuffix will be set to "-tarpaulin"

Optional attributes

• cargoExtraArgs: additional flags to be passed in the cargo invocation
  • Default value: ""
• cargoTarpaulinExtraArgs: additional flags to be passed in the cargo tarpaulin invocation
  • Default value: "--skip-clean --out Xml --output-dir $out"

Native build dependencies

The cargo-tarpaulin package is automatically appended as a native build input to any other nativeBuildInputs specified by the caller.

Remove attributes

The following attributes will be removed before being lowered to cargoBuild. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• cargoExtraArgs
• cargoTarpaulinExtraArgs

lib.cleanCargoSource

cleanCargoSource :: path or drv -> drv

Cleans a source tree to omit things like version control directories as well omit any non-Rust/non-cargo related files. Useful to avoid rebuilding a project when unrelated files are changed (e.g. flake.nix or any other nix files).

The final output will be cleaned by both cleanSourcesFilter (from nixpkgs) and lib.filterCargoSources. See each of them for more details on which files are kept.

If it is necessary to customize which files are kept, a custom filter can be written (which may want to also call lib.filterCargoSources) to achieve the desired behavior.

lib.cleanCargoSource ./.

lib.cleanCargoToml

cleanCargoToml :: set -> set

Cleans all definitions from a Cargo.toml file which are irrelevant for a minimal build of a package's dependencies. See mkDummySrc for more information on how the result is applied.

In general, the following types of attributes are kept from the original input:

• basic package definitions (like name and version)
• dependency definitions
• feature definitions
• workspace definitions
• anything pertaining to project structure (like bin/lib targets, tests, etc.)

lib.cleanCargoToml { cargoToml = ./Cargo.toml; }
# { dependencies = { byteorder = "*"; }; package = { edition = "2021"; name = "simple"; version = "0.1.0"; }; }

Input attributes

• cargoToml: a path to a Cargo.toml file
• cargoTomlContents: the contents of a Cargo.toml file as a string

At least one of the above attributes must be specified, or an error will be raised during evaluation.

lib.crateNameFromCargoToml

crateNameFromCargoToml :: set -> set

Extract a crate's name and version from its Cargo.toml file.

lib.crateNameFromCargoToml { cargoToml = ./Cargo.toml; }
# { pname = "simple"; version = "0.1.0"; }

lib.crateRegistries

crateRegistries :: set

A set of crate registries made available for use in downloading crate sources. The keys are registry URLs as used in the Cargo.lock file (e.g. "registry+https://...") and the values are the download URL for that registry, including any placeholder values cargo is expected to populate for downloads.

This definition can be updated via appendCrateRegistries.

Input attributes

• src: a directory which includes a Cargo.toml file at its root.
• cargoToml: a path to a Cargo.toml file
• cargoTomlContents: the contents of a Cargo.toml file as a string

At least one of the above attributes must be specified, or an error will be raised during evaluation.

Output attributes

• pname: the name of the crate
  • Default value: "cargo-package" if the specified Cargo.toml file did not include a name
• version: the version of the crate
  • Default value: "0.0.1" if the specified Cargo.toml file did not include a version

lib.downloadCargoPackage

downloadCargoPackage :: set -> drv

Download a packaged cargo crate (e.g. from crates.io) and prepare it for vendoring.

Required input attributes

• checksum: the (sha256) checksum recorded in the Cargo.lock file
• name: the name of the crate
• source: the source key recorded in the Cargo.lock file
• version: the version of the crate

lib.downloadCargoPackageFromGit

downloadCargoPackageFromGit :: set -> drv

Download a git repository containing a cargo crate or workspace, and prepare it any crates it contains for vendoring.

Required input attributes

• git: the URL to the repository
• rev: the exact revision to check out

Optional attributes

• ref: the ref (i.e. branch or tag) to which rev belongs to. For branches it should be "refs/head/${branch}" and for tags it should be "refs/tags/${tag}"
  • Default value: null
• allRefs: whether all git refs should be fetched in order to look for the specified rev
  • Default value: true if ref is set to null, false otherwise

lib.findCargoFiles

findCargoFiles :: path -> set of lists

Given a path, recursively search it for any Cargo.toml, .cargo/config or .cargo/config.toml files.

lib.findCargoFiles ./src
# { cargoTomls = [ "..." ]; cargoConfigs = [ "..." ]; }

lib.filterCargoSources

filterCargoSources :: path -> string -> bool

A source filter which when used with cleanSourceWith (from nixpkgs's lib) will retain the following files from a given source:

• Cargo files (Cargo.toml, Cargo.lock, .cargo/config.toml, .cargo/config)
• Rust files (files whose name end with .rs)
• TOML files (files whose name end with .toml)

cleanSourceWith {
  src = ./.;
  filter = lib.filterCargoSources;
}

Note that it is possible to compose source filters, especially if filterCargoSources omits files which are relevant to the build. For example:

let
  # Only keeps markdown files
  markdownFilter = path: _type: match ".*md$" path;
  markdownOrCargo = path: type:
    (markdownFilter path type) || (lib.filterCargoSources path type);
in
cleanSourceWith {
  src = ./.;
  filter = markdownOrCargo;
}

lib.mkCargoDerivation

mkCargoDerivation :: set -> drv

A thin wrapper around stdenv.mkDerivation which includes common hooks for building a derivation using cargo. Except where noted below, all derivation attributes are passed straight through, so any common derivation behavior can be used as expected.

This is a fairly low-level abstraction, so consider using buildPackage or cargoBuild if they fit your needs.

Required attributes

• buildPhaseCargoCommand: A command (likely a cargo invocation) to run during the derivation's build phase. Pre and post build hooks will automatically be run.
• cargoArtifacts: A path (or derivation) which contains an existing cargo target directory, which will be reused at the start of the derivation. Useful for caching incremental cargo builds.
  • This can be prepared via buildDepsOnly
  • Alternatively, any cargo-based derivation which was built with doInstallCargoArtifacts = true will work as well

Optional attributes

• buildPhase: the commands used by the build phase of the derivation
  • Default value: the build phase will run preBuild hooks, print the cargo version, log and evaluate buildPhaseCargoCommand, and run postBuild hooks
• cargoVendorDir: A path (or derivation) of vendored cargo sources which can be consumed without network access. Directory structure should basically follow the output of cargo vendor.
  • Default value: the result of vendorCargoDeps after applying the arguments set (with the respective default values)
• checkPhase: the commands used by the check phase of the derivation
  • Default value: the check phase will run preCheck hooks, log and evaluate checkPhaseCargoCommand, and run postCheck hooks
• checkPhaseCargoCommand: A command (likely a cargo invocation) to run during the derivation's check phase. Pre and post check hooks will automatically be run.
  • Default value: ""
• configurePhase: the commands used by the configure phase of the derivation
  • Default value: the configure phase will run preConfigureHooks hooks, then run postConfigure hooks
• doInstallCargoArtifacts: controls whether cargo's target directory should be copied as an output
  • Default value: true
• installPhase: the commands used by the install phase of the derivation
  • Default value: the install phase will run preInstall hooks, log and evaluate installPhaseCommand, and run postInstall hooks
• installPhaseCommand: the command(s) which are expected to install the derivation's outputs.
  • Default value: "mkdir -p $out"
  • By default an output directory is created such that any other postInstall hooks can successfully run. Consider overriding this value with an appropriate installation commands for the package being built.
• pname: the name of the derivation
  • Default value: the package name listed in Cargo.toml
• pnameSuffix: a suffix appended to pname
  • Default value: ""
• stdenv: the standard build environment to use for this derivation
  • Default value: pkgs.stdenv
• version: the version of the derivation
  • Default value: the version listed in Cargo.toml

Remove attributes

The following attributes will be removed before being lowered to stdenv.mkDerivation. If you absolutely need these attributes present as environment variables during the build, you can bring them back via .overrideAttrs.

• buildPhaseCargoCommand
• checkPhaseCargoCommand
• installPhaseCommand
• pnameSuffix
• stdenv

Native build dependencies and included hooks

The cargo package is automatically appended as a native build input to any other nativeBuildInputs specified by the caller, along with the following hooks:

• cargoHelperFunctionsHook
• configureCargoCommonVarsHook
• configureCargoVendoredDepsHook
• inheritCargoArtifactsHook
• installCargoArtifactsHook
• zstd

lib.mkDummySrc

mkDummySrc :: set -> drv

Converts a given source directory of a cargo workspace to the smallest, most trivial form needed to build all dependencies such that their artifacts can be cached.

The actual source files of the project itself are ignored/replaced with empty programs, such that changes to the source files does not invalidate any build caches. More specifically:

• The Cargo.lock file is kept as-is
  • Any changes to it will invalidate the build cache
• Any cargo configuration files (i.e. files name config or config.toml whose parent directory is named .cargo) are kept as-is.
  • Any changes to these files will invalidate the build cache
• Any files named Cargo.toml are reduced via cleanCargoToml and the result is kept. Only the following changes will result in invalidating the build cache:
  • Any changes to listed dependencies
  • Any changes to feature definitions
  • Any changes to the workspace member metadata
  • Any changes to the [package] definition such as name and version
  • Any changes to the name or path of any target (such as benches, bins, examples, libs, or tests)

Required attributes

• src: a source directory which should be turned into a "dummy" form

Optional attributes

• cargoLock: a path to a Cargo.lock file
  • Default value: src + /Cargo.lock
• extraDummyScript: additional shell script which will be run inside the builder verbatim. Useful for customizing what the dummy sources include by running any arbitrary commands.
  • Default value: ""
  • Note that this script will run in an environment where the original source is not present as doing so would cause a rebuild if any part of the source changed. Additional files can be copied to the derivation's result, but care must be taken that the derivation only depends on (i.e. is rebuilt if) the smallest subset of the original source as required.
  • Here is an example of how to include an entire directory, in this case .cargo, but any other directory would work as well:

    let
    in
    mkDummySrc {
      # The _entire_ source of the project. mkDummySrc will automatically
      # filter out irrelevant files as described above
      src = ./.;
    
      # Note that here we scope the path to just `./.cargo` and not any other
      # directories which may exist at the root of the project. Also note that
      # the entire path is inside of the `${ }` which ensures that the
      # derivation only consumes that directory. Writing `${./.}/.cargo` would
      # incorectly consume the entire source root, and therefore rebuild
      # everything when any file changes, which defeats artifact caching.
      #
      # Also note the `--no-target-directory` flag which ensures the results are
      # copied to `$out/.cargo` instead of something like `$out/HASH-.cargo`
      extraDummyScript = ''
        cp -r ${./.cargo} --no-target-directory $out/.cargo
      '';
    }
    

lib.overrideToolchain

overrideToolchain :: drv -> set

A convenience method to override and use tools (like cargo, clippy, rustfmt, rustc, etc.) from one specific toolchain. The input should be a single derivation which contains all the tools as binaries. For example, this can be the output of oxalica/rust-overlay.

crane.lib.${system}.overrideToolchain myCustomToolchain

lib.registryFromDownloadUrl

registryFromDownloadUrl :: set -> set

Prepares a crate registry into a format that can be passed directly to appendCrateRegistries using the registry's download URL.

If the registry in question has a stable download URL (which either never changes, or it does so very infrequently), then registryFromDownloadUrl is a great and lightweight choice for including the registry. To get started, look up the config.json at the registry's root and copy the value of the dl entry.

If the registry's download endpoint changes more frequently and you would like to infer the configuration directly from a git revision, consider using registryFromGitIndex as an alternative.

Required attributes

• dl: the value of the dl entry in the registry's config.json file
• indexUrl: an HTTP URL to the index

lib.registryFromDownloadUrl {
  dl = "https://crates.io/api/v1/crates";
  indexUrl = "https://github.com/rust-lang/crates.io-index";
}
# { "registry+https://github.com/rust-lang/crates.io-index" = "https://crates.io/api/v1/crates/{crate}/{version}/download"; }

lib.registryFromGitIndex

registryFromGitIndex :: set -> set

Prepares a crate registry into a format that can be passed directly to appendCrateRegistries using a revision of the registry index to infer the download URL.

Note that the specified git revision does not need to track updates to the index itself as long as the pinned revision contains the most recent version of the config.json file. In other words, this commit revision only needs to be updated if the config.json file changes.

Also note that this approach means that the contents of the entire index at the specified revision will be added to the Nix store during evaluation time, and that IFD will need to be enabled. If this is unsatisfactory, consider using registryFromDownloadUrl as a simpler alternative.

Required attributes

• indexUrl: an HTTP URL to the index
• rev: any git revision which contains the latest config.json definition

lib.registryFromGitIndex {
  url = "https://github.com/Hirevo/alexandrie-index";
  rev = "90df25daf291d402d1ded8c32c23d5e1498c6725";
}
# { "registry+https://github.com/Hirevo/alexandrie-index" = "https://crates.polomack.eu/api/v1/crates/{crate}/{version}/download"; }

lib.urlForCargoPackage

urlForCargoPackage :: set -> String

Returns the URL for downloading a particular crate. For now, only crates.io is supported.

Required input attributes

• name: the name of the crate
• source: the source key recorded in the Cargo.lock file
• version: the version of the crate

lib.vendorCargoDeps

vendorCargoDeps :: set -> drv

Creates a derivation which will download all crates referenced by a Cargo.lock file, and prepare a vendored directory which cargo can use for subsequent builds without needing network access.

Each unique crate index will be vendored as its own subdirectory within the output of the derivation. A config.toml file will also be placed at the root of the output which will contain the necessary configurations to point cargo to the vendored directories (i.e. this configuration can be appended to the .cargo/config.toml definition of the project).

Input attributes

• src: a directory which includes a Cargo.lock file at its root.
• cargoLock: a path to a Cargo.lock file
• cargoLockContents: the contents of a Cargo.lock file as a string

At least one of the above attributes must be specified, or an error will be raised during evaluation.

lib.vendorCargoRegistries

vendorCargoRegistries :: set -> set

Creates the derivations necessary to download all crates from all registries referenced by a Cargo.lock file, and prepare the vendored directories which cargo can use for subsequent builds without needing network access.

Input attributes

• cargoConfigs: a list of paths to all .cargo/config.toml files which may appear in the project
• lockPackages: a list of all [[package]] entries found in the project's Cargo.lock file (parsed via builtins.fromTOML)

Output attributes

• config: the configuration entires needed to point cargo to the vendored crates. This is intended to be appended to $CARGO_HOME/config.toml verbatim
• sources: an attribute set of all the newly created cargo sources' names to their location in the Nix store

lib.vendorGitDeps

vendorGitDeps :: set -> set

Creates the derivations necessary to download all crates from all git dependencies referenced by a Cargo.lock file, and prepare the vendored directories which cargo can use for subsequent builds without needing network access.

Input attributes

• lockPackages: a list of all [[package]] entries found in the project's Cargo.lock file (parsed via builtins.fromTOML)

Output attributes

• config: the configuration entires needed to point cargo to the vendored sources. This is intended to be appended to $CARGO_HOME/config.toml verbatim
• sources: an attribute set of all the newly created cargo sources' names to their location in the Nix store

lib.writeTOML

writeTOML :: String -> String -> drv

Takes a file name and an attribute set, converts the set to a TOML document and writes it to a file with the given name.

lib.writeTOML "foo.toml" { foo.bar = "baz"; }
# «derivation /nix/store/...-foo.toml.drv»

Hooks

lib.cargoHelperFunctionsHook

Defines helper functions for internal use. It is probably not a great idea to depend on these directly as their behavior can change at any time, but it is worth documenting them just in case:

• Defines a cargo() function which will immediately invoke the cargo command found on the $PATH after echoing the exact arguments that were passed in. Useful for automatically logging all cargo invocations to the log.
• Defines a cargoWithProfile() function which will invoke cargo with the provided arguments. If $CARGO_PROFILE is set, then --profile $CARGO_PROFILE will be injected into the cargo invocation
  • Note: a default value of $CARGO_PROFILE is set via configureCargoCommonVarsHook. You can set CARGO_PROFILE = "something" in your derivation to change which profile is used, or set CARGO_PROFILE = ""; to omit it altogether.

lib.configureCargoCommonVarsHook

Defines configureCargoCommonVars() which will set various common cargo-related variables, such as honoring the amount of parallelism dictated by Nix, disabling incremental artifacts, etc. More specifically:

• CARGO_BUILD_INCREMENTAL is set to false if not already defined
• CARGO_BUILD_JOBS is set to $NIX_BUILD_CORES if not already defined
• CARGO_HOME is set to $PWD/.cargo-home if not already defined.
  • The directory that CARGO_HOME points to will be created
• CARGO_PROFILE is set to release if not already defined.
  • Note that this is is used internally specify a cargo profile (e.g. cargo build --profile release) and not something natively understood by cargo.
• RUST_TEST_THREADS is set to $NIX_BUILD_CORES if not already defined

Automatic behavior: runs as a post-patch hook

lib.configureCargoVendoredDepsHook

Defines configureCargoVendoredDeps() which will prepare cargo to use a directory of vendored crate sources. It takes two positional arguments:

1. a path to the vendored sources
   • If not specified, the value of $cargoVendorDir will be used
   • If cargoVendorDir is not specified, an error will be raised
2. a path to a cargo config file to modify
   • If not specified, the value of $CARGO_HOME/config.toml will be used
   • This cargo config file will be appended with a stanza which will instruct cargo to use the vendored sources (instead of downloading the sources directly) as follows:
     • If the vendored directory path contains a file named config.toml, then its contents will be appended to the specified cargo config path.
     • Otherwise the entire vendored directory path will be treated as if it only vendors the crates.io index and will be configured as such.

Automatic behavior: if cargoVendorDir is set, then configureCargoVendoredDeps "$cargoVendorDir" "$CARGO_HOME/config.toml" will be run as a pre configure hook.

lib.inheritCargoArtifactsHook

Defines inheritCargoArtifacts() which will pre-populate cargo's artifact directory using a previous derivation. It takes two positional arguments:

1. a path to the previously prepared artifacts
   • If not specified, the value of $cargoArtifacts will be used
   • If cargoArtifacts is not specified, an error will be raised
   • If the specified path is a directory which contains a file called target.tar.zst, then that file will be used during unpacking
   • The previously prepared artifacts are expected to be a zstd compressed tarball
2. the path to cargo's artifact directory, where the previously prepared artifacts should be unpacked
   • If not specified, the value of $CARGO_TARGET_DIR will be used
   • If CARGO_TARGET_DIR is not set, cargo's default target location (i.e. ./target) will be used.

Automatic behavior: if cargoArtifacts is set, then inheritCargoArtifacts "$cargoArtifacts" "$CARGO_TARGET_DIR" will be run as a post patch hook.

Required nativeBuildInputs: assumes zstd is available on the $PATH

lib.installCargoArtifactsHook

Defines prepareAndInstallCargoArtifactsDir() which handles installing cargo's artifact directory to the derivation's output. It takes two positional arguments:

1. the installation directory for the output.
   • If not specified, the value of $out will be used
   • Cargo's artifact directory will be compressed as a reproducible tarball with zstd compression. It will be written to this directory and named target.tar.zstd
2. the path to cargo's artifact directory
   • If not specified, the value of $CARGO_TARGET_DIR will be used
   • If CARGO_TARGET_DIR is not set, cargo's default target location (i.e. ./target) will be used.

Automatic behavior: if doInstallCargoArtifacts is set to 1, then prepareAndInstallCargoArtifactsDir "$out" "$CARGO_TARGET_DIR" will be run as a post install hook.

Required nativeBuildInputs: assumes zstd is available on the $PATH

lib.installFromCargoBuildLogHook

Defines installFromCargoBuildLog() which will use a build log produced by cargo to find and install any binaries and libraries which have been built. It takes two positional arguments:

1. a path to where artifacts should be installed
   • If not specified, the value of $out will be used
   • Binaries will be installed in a bin subdirectory
   • Libraries will be installed in a lib subdirectory
     • Note that only library targets with the staticlib and cdylib crate-types will be installed. Library targets with the rlib crate-type will be ignored
2. a path to a JSON formatted build log written by cargo
   • If not specified, the value of $cargoBuildLog will be used
   • If cargoBuildLog is not set, an error will be raised
   • This log can be captured, for example, via cargo build --message-format json-render-diagnostics >cargo-build.json

Automatic behavior: none

Required nativeBuildInputs: assumes cargo and jq are available on the $PATH

lib.removeReferencesToVendoredSourcesHook

Defines removeReferencesToVendoredSources() which handles removing all references to vendored sources from the installed binaries, which ensures that nix does not consider the binaries as having a (runtime) dependency on the sources themselves. It takes two positional arguments:

1. the installation directory for the output.
   • If not specified, the value of $out will be used
   • If out is not specified, an error will be raised
2. a path to the vendored sources
   • If not specified, the value of $cargoVendorDir will be used
   • If cargoVendorDir is not specified, an error will be raised
   • Note: it is expected that this directory has the exact structure as would be produced by lib.vendorCargoDeps

Automatic behavior: if cargoVendorDir is set and doNotRemoveReferencesToVendorDir is not set, then removeReferencesToVendoredSources "$out" "$cargoVendorDir" will be run as a post install hook.

Required nativeBuildInputs: assumes remove-references-to is available on the $PATH