[Backport release-24.11] rustPlatform.fetchCargoVendor: init

doc/languages-frameworks/rust.section.md

@@ -64,10 +64,18 @@ hash using `nix-hash --to-sri --type sha256 "<original sha256>"`.
 ```
 
 Exception: If the application has cargo `git` dependencies, the `cargoHash`
-approach will not work, and you will need to copy the `Cargo.lock` file of the application
-to nixpkgs and continue with the next section for specifying the options of the `cargoLock`
-section.
+approach will not work by default. In this case, you can set `useFetchCargoVendor = true`
+to use an improved fetcher that supports handling `git` dependencies.
 
+```nix
+{
+  useFetchCargoVendor = true;
+  cargoHash = "sha256-RqPVFovDaD2rW31HyETJfQ0qVwFxoGEvqkIgag3H6KU=";
+}
+```
+
+If this method still does not work, you can resort to copying the `Cargo.lock` file into nixpkgs
+and importing it as described in the [next section](#importing-a-cargo.lock-file).
 
 Both types of hashes are permitted when contributing to nixpkgs. The
 Cargo hash is obtained by inserting a fake checksum into the
@@ -462,6 +470,17 @@ also be used:
   the `Cargo.lock`/`Cargo.toml` files need to be patched before
   vendoring.
 
+In case the lockfile contains cargo `git` dependencies, you can use
+`fetchCargoVendor` instead.
+```nix
+{
+  cargoDeps = rustPlatform.fetchCargoVendor {
+    inherit src;
+    hash = "sha256-RqPVFovDaD2rW31HyETJfQ0qVwFxoGEvqkIgag3H6KU=";
+  };
+}
+```
+
 If a `Cargo.lock` file is available, you can alternatively use the
 `importCargoLock` function. In contrast to `fetchCargoTarball`, this
 function does not require a hash (unless git dependencies are used)

pkgs/build-support/rust/build-rust-package/default.nix

@@ -1,6 +1,7 @@
 { lib
 , importCargoLock
 , fetchCargoTarball
+, fetchCargoVendor
 , stdenv
 , callPackage
 , cargoBuildHook
@@ -36,6 +37,8 @@
 , cargoDepsHook ? ""
 , buildType ? "release"
 , meta ? {}
+, useFetchCargoVendor ? false
+, cargoDeps ? null
 , cargoLock ? null
 , cargoVendorDir ? null
 , checkType ? buildType
@@ -58,15 +61,22 @@
 , buildAndTestSubdir ? null
 , ... } @ args:
 
-assert cargoVendorDir == null && cargoLock == null
+assert cargoVendorDir == null && cargoDeps == null && cargoLock == null
     -> !(args ? cargoSha256 && args.cargoSha256 != null) && !(args ? cargoHash && args.cargoHash != null)
-    -> throw "cargoHash, cargoVendorDir, or cargoLock must be set";
+    -> throw "cargoHash, cargoVendorDir, cargoDeps, or cargoLock must be set";
 
 let
 
-  cargoDeps =
+  cargoDeps' =
     if cargoVendorDir != null then null
+    else if cargoDeps != null then cargoDeps
     else if cargoLock != null then importCargoLock cargoLock
+    else if useFetchCargoVendor then fetchCargoVendor ({
+      inherit src srcs sourceRoot preUnpack unpackPhase postUnpack;
+      name = cargoDepsName;
+      patches = cargoPatches;
+      hash = args.cargoHash;
+    } // depsExtraArgs)
     else fetchCargoTarball ({
       inherit src srcs sourceRoot preUnpack unpackPhase postUnpack cargoUpdateHook;
       name = cargoDepsName;
@@ -94,15 +104,16 @@ in
 # See https://os.phil-opp.com/testing/ for more information.
 assert useSysroot -> !(args.doCheck or true);
 
-stdenv.mkDerivation ((removeAttrs args [ "depsExtraArgs" "cargoUpdateHook" "cargoLock" ]) // lib.optionalAttrs useSysroot {
+stdenv.mkDerivation ((removeAttrs args [ "depsExtraArgs" "cargoUpdateHook" "cargoDeps" "cargoLock" ]) // lib.optionalAttrs useSysroot {
   RUSTFLAGS = "--sysroot ${sysroot} " + (args.RUSTFLAGS or "");
 } // lib.optionalAttrs (stdenv.isDarwin && buildType == "debug") {
   RUSTFLAGS =
     "-C split-debuginfo=packed "
     + lib.optionalString useSysroot "--sysroot ${sysroot} "
     + (args.RUSTFLAGS or "");
 } // {
-  inherit buildAndTestSubdir cargoDeps;
+  cargoDeps = cargoDeps';
+  inherit buildAndTestSubdir;
 
   cargoBuildType = buildType;
 

pkgs/build-support/rust/fetch-cargo-tarball/default.nix

@@ -120,8 +120,9 @@ stdenv.mkDerivation (
           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 "This is not supported in the default fixed-output derivation fetcher."
+          echo "Set \`useFetchCargoVendor = true\` / use fetchCargoVendor"
+          echo "or use cargoLock.lockFile / importCargoLock instead."
           echo
 
           exit 1