directory into a tar.gz archive.

The tarball with vendored dependencies contains a directory with the
package's `name`, which is normally composed of `pname` and
`version`. This means that the vendored dependencies hash
(`cargoHash`) is dependent on the package name and
version. The `cargoDepsName` attribute can be used to use another name
for the directory of vendored dependencies. For example, the hash can
be made invariant to the version by setting `cargoDepsName` to
`pname`:

```nix
rustPlatform.buildRustPackage (finalAttrs: {
  pname = "broot";
  version = "1.2.0";

  src = fetchCrate {
    inherit (finalAttrs) pname version;
    hash = "sha256-aDQA4A5mScX9or3Lyiv/5GyAehidnpKKE0grhbP1Ctc=";
  };

  cargoHash = "sha256-iDYh52rj1M5Uupvbx2WeDd/jvQZ+2A50V5rp5e2t7q4=";
  cargoDepsName = finalAttrs.pname;

  # ...
})
```

### Importing a `Cargo.lock` file {#importing-a-cargo.lock-file}

Using a vendored hash (`cargoHash`) is tedious when using
`buildRustPackage` within a project, since it requires that the hash
is updated after every change to `Cargo.lock`. Therefore,
`buildRustPackage` also supports vendoring dependencies directly from
a `Cargo.lock` file using the `cargoLock` argument. For example:

```nix
rustPlatform.buildRustPackage {
  pname = "myproject";
  version = "1.0.0";

  cargoLock = {
    lockFile = ./Cargo.lock;
  };

  # ...
}
```

This will retrieve the dependencies using fixed-output derivations from
the specified lockfile.

One caveat is that `Cargo.lock` cannot be patched in the `patchPhase`
because it runs after the dependencies have already been fetched. If
you need to patch or generate the lockfile you can alternatively set
`cargoLock.lockFileContents` to a string of its contents:

```nix
rustPlatform.buildRustPackage {
  pname = "myproject";
  version = "1.0.0";

  cargoLock =
    let
      fixupLockFile = path: f (builtins.readFile path);
    in
    {
      lockFileContents = fixupLockFile ./Cargo.lock;
    };

  # ...
}
```

If the upstream source repository lacks a `Cargo.lock` file, you must add one
to `src`, as it is essential for building a Rust package. Setting
`cargoLock.lockFile` or `cargoLock.lockFileContents` will not automatically add
a `Cargo.lock` file to `src`. A straightforward solution is to use:

```nix
{
  postPatch = ''
    ln -s ${./Cargo.lock} Cargo.lock
  '';
}
```

The output hash of each dependency that uses a git source must be
specified in the `outputHashes` attribute. For example:

```nix
rustPlatform.buildRustPackage {
  pname = "myproject";
  version = "1.0.0";

  cargoLock = {
    lockFile = ./Cargo.lock;
    outputHashes = {
      "finalfusion-0.14.0" = "17f4bsdzpcshwh74w5z119xjy2if6l2wgyjy56v621skr2r8y904";
    };
  };

  # ...
}
```

If you do not specify an output hash for a git dependency, building
the package will fail and inform you of which crate needs to be
added. To find the correct hash, you can first use `lib.fakeSha256` or
`lib.fakeHash` as a stub hash. Building the package (and thus the
vendored dependencies) will then inform you of the correct hash.

For usage outside nixpkgs, `allowBuiltinFetchGit` could be used to
avoid having to specify `outputHashes`. For example:

```nix
rustPlatform.buildRustPackage {
  pname = "myproject";
  version = "1.0.0";

  cargoLock = {
    lockFile = ./Cargo.lock;
    allowBuiltinFetchGit = true;
  };

  # ...
}
```

### Cargo features {#cargo-features}

You can disable default features using `buildNoDefaultFeatures`, and
extra features can be added with `buildFeatures`.

If you want to use different features for check phase, you can use
`checkNoDefaultFeatures` and `checkFeatures`. They are only passed to
`cargo test` and not `cargo build`. If left unset, they default to
`buildNoDefaultFeatures` and `buildFeatures`.

For example:

```nix
rustPlatform.buildRustPackage {
  pname = "myproject";
  version = "1.0.0";

  buildNoDefaultFeatures = true;
  buildFeatures = [
    "color"
    "net"
  ];

  # disable network features in tests