[build] Update rules_rust

.bazelrc

@@ -273,8 +273,10 @@ build:asan --test_env=KJ_CLEAN_SHUTDOWN=1
 # Enable ASan, LSan support in V8
 build:asan --copt="-DV8_USE_ADDRESS_SANITIZER"
 build:asan --per_file_copt='external/.*v8@-DADDRESS_SANITIZER,-DLEAK_SANITIZER'
-# One toolchain per host; resolution picks the one matching the (host-parented) asan platform.
+# One toolchain per host, plus its cargo toolchain; resolution picks the one matching the
+# (host-parented) asan platform.
 build:asan --extra_toolchains=//build/rust:asan_toolchain_linux_x86_64,//build/rust:asan_toolchain_linux_aarch64,//build/rust:asan_toolchain_macos_aarch64
+build:asan --extra_toolchains=//build/rust:asan_toolchain_linux_x86_64_cargo,//build/rust:asan_toolchain_linux_aarch64_cargo,//build/rust:asan_toolchain_macos_aarch64_cargo
 build:asan --@rules_rust//:extra_rustc_flag=-Zsanitizer=address
 
 # thread sanitizer (https://github.com/google/sanitizers/wiki/ThreadSanitizerCppManual)
@@ -305,8 +307,10 @@ build:tsan-common --copt="-DV8_IS_TSAN"
 build:tsan-common --per_file_copt='external/.*v8@-DTHREAD_SANITIZER'
 # Perfetto also requires this define to enable its shared-memory scraping annotations.
 build:tsan-common --per_file_copt='external/.*perfetto@-DTHREAD_SANITIZER'
-# One toolchain per host; resolution picks the one matching the (host-parented) tsan platform.
+# One toolchain per host, plus its cargo toolchain; resolution picks the one matching the
+# (host-parented) tsan platform.
 build:tsan-common --extra_toolchains=//build/rust:tsan_toolchain_linux_x86_64,//build/rust:tsan_toolchain_macos_aarch64
+build:tsan-common --extra_toolchains=//build/rust:tsan_toolchain_linux_x86_64_cargo,//build/rust:tsan_toolchain_macos_aarch64_cargo
 build:tsan-common --@rules_rust//:extra_rustc_flag=-Zsanitizer=thread
 
 # Linux x86_64.

build/deps/formatters/rustfmt_repository.bzl

@@ -15,18 +15,6 @@ def _rustfmt_standalone_repository_impl(repository_ctx):
     iso_date = repository_ctx.attr.iso_date
     proxy = PROXY_URL
 
-    # Download the rustfmt component (contains bin/rustfmt and bin/cargo-fmt).
-    rustfmt_url = proxy + _URL_TEMPLATE.format(
-        iso_date = iso_date,
-        component = "rustfmt",
-        triple = triple,
-    )
-    repository_ctx.download_and_extract(
-        url = rustfmt_url,
-        sha256 = repository_ctx.attr.rustfmt_sha256,
-        stripPrefix = "rustfmt-nightly-{}/rustfmt-preview".format(triple),
-    )
-
     # Download the rustc component (contains shared libraries that rustfmt
     # dynamically links against, e.g. librustc_driver-*.so / .dylib).
     rustc_url = proxy + _URL_TEMPLATE.format(
@@ -40,6 +28,22 @@ def _rustfmt_standalone_repository_impl(repository_ctx):
         stripPrefix = "rustc-nightly-{}/rustc".format(triple),
     )
 
+    # Delete binaries to reduce disk space usage, we only need librustc_driver
+    repository_ctx.delete("bin")
+    repository_ctx.delete("lib/rustlib")
+
+    # Download the rustfmt component (contains bin/rustfmt and bin/cargo-fmt).
+    rustfmt_url = proxy + _URL_TEMPLATE.format(
+        iso_date = iso_date,
+        component = "rustfmt",
+        triple = triple,
+    )
+    repository_ctx.download_and_extract(
+        url = rustfmt_url,
+        sha256 = repository_ctx.attr.rustfmt_sha256,
+        stripPrefix = "rustfmt-nightly-{}/rustfmt-preview".format(triple),
+    )
+
     # Create a wrapper script that sets the library path so the dynamically-linked
     # rustfmt binary can find its libraries.  We embed absolute paths because the
     # wrapper may be copied to bazel-bin by native_binary.

build/deps/gen/build_deps.MODULE.bazel

@@ -104,7 +104,7 @@ bazel_dep(name = "rules_oci", version = "2.3.0")
 bazel_dep(name = "rules_python", version = "2.4.5")
 
 # rules_rust
-bazel_dep(name = "rules_rust", version = "0.74.0")
+bazel_dep(name = "rules_rust", version = "0.75.0")
 single_version_override(
     module_name = "rules_rust",
     patch_strip = 1,

build/rust/sanitizer_toolchain.bzl

@@ -4,6 +4,7 @@
 
 """Per-host sanitizer-instrumented Rust toolchains (see //build/rust:BUILD.bazel)."""
 
+load("@rules_rust//cargo:cargo_toolchain.bzl", "cargo_toolchain")
 load("@rules_rust//rust:toolchain.bzl", "rust_toolchain")
 load("//build/deps:gen/build_deps.bzl", "RUST_NIGHTLY_DATE", "RUST_NIGHTLY_VERSION")
 load(":build_std.bzl", "compiler_runtime_files", "instrumented_rust_std")
@@ -109,7 +110,6 @@ def sanitizer_rust_toolchain(name, sanitizer, host):
         name = name + "_impl",
         allocator_library = "@rules_rust//ffi/rs:empty",
         binary_ext = "",
-        cargo = h.rust_tools + "//:cargo",
         cargo_clippy = h.rust_tools + "//:cargo_clippy_bin",
         channel = "nightly",
         clippy_driver = h.rust_tools + "//:clippy_driver_bin",
@@ -147,3 +147,22 @@ def sanitizer_rust_toolchain(name, sanitizer, host):
         toolchain = ":" + name + "_impl",
         toolchain_type = "@rules_rust//rust:toolchain",
     )
+
+    cargo_toolchain(
+        name = name + "_cargo_impl",
+        cargo = h.rust_tools + "//:cargo",
+        channel = "nightly",
+        iso_date = RUST_NIGHTLY_DATE,
+        tags = ["manual"],
+        version = RUST_NIGHTLY_VERSION,
+    )
+
+    native.toolchain(
+        name = name + "_cargo",
+        exec_compatible_with = host_constraints,
+        tags = ["manual"],
+        target_compatible_with = host_constraints + [constraint],
+        target_settings = ["@rules_rust//rust/toolchain/channel:nightly"],
+        toolchain = ":" + name + "_cargo_impl",
+        toolchain_type = "@rules_rust//cargo:toolchain_type",
+    )