diff --git a/pkgs/build-support/rust/fetch-cargo-tarball/default.nix b/pkgs/build-support/rust/fetch-cargo-tarball/default.nix
index adbfe98d8103..a1fa2f074f84 100644
--- a/pkgs/build-support/rust/fetch-cargo-tarball/default.nix
+++ b/pkgs/build-support/rust/fetch-cargo-tarball/default.nix
@@ -1,116 +1,143 @@
-{ lib, stdenv, cacert, git, cargo, python3 }:
-let cargo-vendor-normalise = stdenv.mkDerivation {
-  name = "cargo-vendor-normalise";
-  src = ./cargo-vendor-normalise.py;
-  nativeBuildInputs = [ python3.pkgs.wrapPython ];
-  dontUnpack = true;
-  installPhase = "install -D $src $out/bin/cargo-vendor-normalise";
-  pythonPath = [ python3.pkgs.toml ];
-  postFixup = "wrapPythonPrograms";
-  doInstallCheck = true;
-  installCheckPhase = ''
-    # check that ../fetchcargo-default-config.toml is a fix point
-    reference=${../fetchcargo-default-config.toml}
-    < $reference $out/bin/cargo-vendor-normalise > test;
-    cmp test $reference
-  '';
-  preferLocalBuild = true;
-};
+{
+  lib,
+  stdenv,
+  cacert,
+  git,
+  cargo,
+  python3,
+}:
+let
+  cargo-vendor-normalise = stdenv.mkDerivation {
+    name = "cargo-vendor-normalise";
+    src = ./cargo-vendor-normalise.py;
+    nativeBuildInputs = [ python3.pkgs.wrapPython ];
+    dontUnpack = true;
+    installPhase = "install -D $src $out/bin/cargo-vendor-normalise";
+    pythonPath = [ python3.pkgs.toml ];
+    postFixup = "wrapPythonPrograms";
+    doInstallCheck = true;
+    installCheckPhase = ''
+      # check that ../fetchcargo-default-config.toml is a fix point
+      reference=${../fetchcargo-default-config.toml}
+      < $reference $out/bin/cargo-vendor-normalise > test;
+      cmp test $reference
+    '';
+    preferLocalBuild = true;
+  };
 in
-{ name ? "cargo-deps"
-, src ? null
-, srcs ? []
-, patches ? []
-, sourceRoot ? ""
-, cargoUpdateHook ? ""
-, nativeBuildInputs ? []
-, ...
-} @ args:
+{
+  name ? "cargo-deps",
+  src ? null,
+  srcs ? [ ],
+  patches ? [ ],
+  sourceRoot ? "",
+  cargoUpdateHook ? "",
+  nativeBuildInputs ? [ ],
+  ...
+}@args:
 
-let hash_ =
-  if args ? hash then
-    {
-      outputHashAlgo = if args.hash == "" then "sha256" else null;
-      outputHash = args.hash;
-    }
-  else if args ? sha256 then { outputHashAlgo = "sha256"; outputHash = args.sha256; }
-  else throw "fetchCargoTarball requires a hash for ${name}";
-in stdenv.mkDerivation ({
-  name = "${name}-vendor.tar.gz";
-  nativeBuildInputs = [ cacert git cargo-vendor-normalise cargo ] ++ nativeBuildInputs;
+let
+  hash_ =
+    if args ? hash then
+      {
+        outputHashAlgo = if args.hash == "" then "sha256" else null;
+        outputHash = args.hash;
+      }
+    else if args ? sha256 then
+      {
+        outputHashAlgo = "sha256";
+        outputHash = args.sha256;
+      }
+    else
+      throw "fetchCargoTarball requires a hash for ${name}";
+in
+stdenv.mkDerivation (
+  {
+    name = "${name}-vendor.tar.gz";
+    nativeBuildInputs = [
+      cacert
+      git
+      cargo-vendor-normalise
+      cargo
+    ] ++ nativeBuildInputs;
 
-  buildPhase = ''
-    runHook preBuild
+    buildPhase = ''
+      runHook preBuild
 
-    # Ensure deterministic Cargo vendor builds
-    export SOURCE_DATE_EPOCH=1
+      # Ensure deterministic Cargo vendor builds
+      export SOURCE_DATE_EPOCH=1
 
-    if [[ ! -f Cargo.lock ]]; then
-        echo
-        echo "ERROR: The Cargo.lock file doesn't exist"
-        echo
-        echo "Cargo.lock is needed to make sure that cargoHash/cargoSha256 doesn't change"
-        echo "when the registry is updated."
-        echo
+      if [[ ! -f Cargo.lock ]]; then
+          echo
+          echo "ERROR: The Cargo.lock file doesn't exist"
+          echo
+          echo "Cargo.lock is needed to make sure that cargoHash/cargoSha256 doesn't change"
+          echo "when the registry is updated."
+          echo
 
-        exit 1
-    fi
+          exit 1
+      fi
 
-    # Keep the original around for copyLockfile
-    cp Cargo.lock Cargo.lock.orig
+      # Keep the original around for copyLockfile
+      cp Cargo.lock Cargo.lock.orig
 
-    export CARGO_HOME=$(mktemp -d cargo-home.XXX)
-    CARGO_CONFIG=$(mktemp cargo-config.XXXX)
+      export CARGO_HOME=$(mktemp -d cargo-home.XXX)
+      CARGO_CONFIG=$(mktemp cargo-config.XXXX)
 
-    if [[ -n "$NIX_CRATES_INDEX" ]]; then
-    cat >$CARGO_HOME/config.toml <<EOF
-    [source.crates-io]
-    replace-with = 'mirror'
-    [source.mirror]
-    registry = "$NIX_CRATES_INDEX"
-    EOF
-    fi
+      if [[ -n "$NIX_CRATES_INDEX" ]]; then
+      cat >$CARGO_HOME/config.toml <<EOF
+      [source.crates-io]
+      replace-with = 'mirror'
+      [source.mirror]
+      registry = "$NIX_CRATES_INDEX"
+      EOF
+      fi
 
-    ${cargoUpdateHook}
+      ${cargoUpdateHook}
 
-    # Override the `http.cainfo` option usually specified in `.cargo/config`.
-    export CARGO_HTTP_CAINFO=${cacert}/etc/ssl/certs/ca-bundle.crt
+      # Override the `http.cainfo` option usually specified in `.cargo/config`.
+      export CARGO_HTTP_CAINFO=${cacert}/etc/ssl/certs/ca-bundle.crt
 
-    if grep '^source = "git' Cargo.lock; then
-        echo
-        echo "ERROR: The Cargo.lock contains git dependencies"
-        echo
-        echo "This is currently not supported in the fixed-output derivation fetcher."
-        echo "Use cargoLock.lockFile / importCargoLock instead."
-        echo
+      if grep '^source = "git' Cargo.lock; then
+          echo
+          echo "ERROR: The Cargo.lock contains git dependencies"
+          echo
+          echo "This is currently not supported in the fixed-output derivation fetcher."
+          echo "Use cargoLock.lockFile / importCargoLock instead."
+          echo
 
-        exit 1
-    fi
+          exit 1
+      fi
 
-    cargo vendor $name --respect-source-config | cargo-vendor-normalise > $CARGO_CONFIG
+      cargo vendor $name --respect-source-config | cargo-vendor-normalise > $CARGO_CONFIG
 
-    # Create an empty vendor directory when there is no dependency to vendor
-    mkdir -p $name
-    # Add the Cargo.lock to allow hash invalidation
-    cp Cargo.lock.orig $name/Cargo.lock
+      # Create an empty vendor directory when there is no dependency to vendor
+      mkdir -p $name
+      # Add the Cargo.lock to allow hash invalidation
+      cp Cargo.lock.orig $name/Cargo.lock
 
-    # Packages with git dependencies generate non-default cargo configs, so
-    # always install it rather than trying to write a standard default template.
-    install -D $CARGO_CONFIG $name/.cargo/config;
+      # Packages with git dependencies generate non-default cargo configs, so
+      # always install it rather than trying to write a standard default template.
+      install -D $CARGO_CONFIG $name/.cargo/config;
 
-    runHook postBuild
-  '';
+      runHook postBuild
+    '';
 
-  # Build a reproducible tar, per instructions at https://reproducible-builds.org/docs/archives/
-  installPhase = ''
-    tar --owner=0 --group=0 --numeric-owner --format=gnu \
-        --sort=name --mtime="@$SOURCE_DATE_EPOCH" \
-        -czf $out $name
-  '';
+    # Build a reproducible tar, per instructions at https://reproducible-builds.org/docs/archives/
+    installPhase = ''
+      tar --owner=0 --group=0 --numeric-owner --format=gnu \
+          --sort=name --mtime="@$SOURCE_DATE_EPOCH" \
+          -czf $out $name
+    '';
 
-  inherit (hash_) outputHashAlgo outputHash;
+    inherit (hash_) outputHashAlgo outputHash;
 
-  impureEnvVars = lib.fetchers.proxyImpureEnvVars ++ [ "NIX_CRATES_INDEX" ];
-} // (builtins.removeAttrs args [
-  "name" "sha256" "cargoUpdateHook" "nativeBuildInputs"
-]))
+    impureEnvVars = lib.fetchers.proxyImpureEnvVars ++ [ "NIX_CRATES_INDEX" ];
+  }
+  // (builtins.removeAttrs args [
+    "name"
+    "sha256"
+    "cargoUpdateHook"
+    "nativeBuildInputs"
+  ])
+)