chore(bazel): upgrade rules_rust to 0.74.0

[basvandijk]

Upgrades rules_rust from 0.71.3 to 0.74.0, stops depending on the dfinity/rules_rust fork, and drops two local patches that 0.74.0 makes redundant.

Drops the fork

The pin was an archive_override on dfinity/rules_rust, whose sole commit adds a strip_level_select tag class (bazelbuild/rules_rust#4167, still open upstream). That tag's only caller was removed in 9e29205 when hermetic-llvm replaced zig cc — clang emits deterministic debug info, so the strip_level_select(none) workaround went away with it. strip_level now appears nowhere in the repo outside the patch file, so the fork is dead code.

-bazel_dep(name = "rules_rust", version = "0.71.3")
-archive_override(
+bazel_dep(name = "rules_rust", version = "0.74.0")
+single_version_override(
     module_name = "rules_rust",
-    integrity = "sha256-5GXwZtp5VlNxMI+dolYYxhyhG5f5ReZ5qz30gAbPsrg=",
     patch_strip = 1,
     patches = ["//bazel:rules_rust_static_runtime.patch"],
-    strip_prefix = "rules_rust-f8f382c7e351a797242ce4a92262342f8994e265",
-    type = "tar.gz",
-    urls = ["https://codeload.github.com/dfinity/rules_rust/tar.gz/f8f382c7e351a797242ce4a92262342f8994e265"],
 )

No integrity hash, no strip_prefix, no URL, and no fork to rebase on every future release — a bump is now a one-line version change. Checked before switching: BCR's rules_rust/0.74.0/source.json carries no patches of its own, and rules_rust is depended on only by the root module (bazel mod explain rules_rust), so nothing else can pull MVS off 0.74.0.

Regenerates bazel/rules_rust_static_runtime.patch

The rust_doc_test half of the patch is upstream as of 0.74.0 (#4220, commit ed7afd2fc) and is a superset of ours — it threads the runtime libs through rustdoc_compile_action's return value rather than recomputing them, adds an empty-lib-root guard we lacked (an empty root would emit --strip_substring=/, which the writer applies as a plain string replacement), and ships a unit test. So the patch no longer carries it.

What remains is the dylib/cdylib static-runtime preference, which is still not upstream and has no replacement mechanism (no new unwindlib, toolchain or rule attribute controls C++ runtime linkage in this range). #4220 also introduced a new site in rustdoc.bzl that picks the dynamic runtime for dylib/cdylib, which the old patch would have missed — leaving a cdylib doc test with the static runtime in its action inputs but the dynamic runtime's names in its -l flags. The policy therefore now lives in a single exported cc_runtime_libs helper, shared by all three sites that choose a runtime (collect_inputs, _add_native_link_flags, and rustdoc's doc-test link flags), so inputs and link flags stay consistent by construction.

The patch applies with zero fuzz and zero offset (git apply --check and patch -F0), verified against the release tarball specifically, not just the git tag.

Drops bazel/rustix.patch

That patch deleted rustix's can_compile() probe artifact from OUT_DIR — which rules_rust captures as a cacheable CargoBuildScriptRun output — because the artifact was not byte-reproducible. 0.74.0 makes it unnecessary: #4202 adds --remap-path-prefix=${pwd}=. to the CARGO_ENCODED_RUSTFLAGS that cargo_build_script passes to build scripts, and rustix's can_compile() forwards all of them to its probe rustc.

Follow-ups (not in this PR)

• The remaining dylib/cdylib half of the static-runtime patch has no upstream issue. Opening one would let it retire the way the doc-test half just did — though upstream deliberately links the dynamic runtime for shared libraries (its own runtime_libs_test/shared_library asserts exactly that), so it would need a toolchain-level opt-in rather than a straight behaviour change.
• .claude/CLAUDE.md's repin trigger could mention the rules_rust pin, since a bump on its own requires ./bin/bazel-pin.sh --force.
• If the rustix probe ever regresses (a toolchain bump, or anything adding a remap-scope rustflag), the fix is rules_rust 0.74.0's new remove_nondeterministic_out_dir_files: appending rustix_test_can_compile to --@rules_rust//cargo/settings:out_dir_volatile_file_basenames (re-listing its seven defaults, since the flag replaces rather than extends) empties OUT_DIR again with no crate patch and no repin. That, not a resurrected bazel/rustix.patch.
• Worth an upstream issue: cargo_build_script could pass the same ${output_base}/${exec_root} remaps that rustc.bzl already passes, closing the symlink gap described above.
• The dfinity/rules_rust fork branches can be deleted once this merges; nothing will reference the fork any more.

🤖 Generated with Claude Code

[Copilot]

🔵 Needs a closer look

The repo-wide dependency upgrade, upstream-internal patch, and large generated lockfile warrant final human verification.

Pull request overview

Upgrades rules_rust to upstream 0.74.0 while preserving required static C++ runtime linkage.

Changes:

• Replaces the fork override with a registry-based override.
• Refactors and reduces the static-runtime patch.
• Repins the generated crate-universe lockfile.

File summaries

File	Description
bazel/rust.MODULE.bazel	Updates and patches rules_rust 0.74.0.
bazel/rules_rust_static_runtime.patch	Centralizes shared-library runtime selection.
Cargo.Bazel.json.lock	Regenerates crate-universe metadata.

Review details

• Files reviewed: 2/3 changed files
• Comments generated: 0
• Review effort level: Balanced

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[nmattia]

bazel/rustix.patch may now be redundant: upstream bazelbuild/rules_rust#4202 fixes issue #4201, the same rustix build-script probe defect that patch works around. Worth checking separately rather than in a version bump.

Let's check here; no point carrying a patch that's unnecessary

[Copilot]

🔵 Needs a closer look

The toolchain-wide upgrade and custom runtime-linking patch affect production shared libraries and warrant final human validation.

Review details

• Files reviewed: 4/6 changed files
• Comments generated: 0 new
• Review effort level: Balanced