Test crc-fast 1.4 to verify canary catches dependency issues

.github/workflows/ci.yml

@@ -333,6 +333,38 @@ jobs:
       shell: bash
       run: cross test --target ${{ matrix.target }} --manifest-path "aws/rust-runtime/Cargo.toml" ${{ matrix.test_aws_exclude }} --workspace
 
+  # Test runtime crates on multiple architectures to catch architecture-specific issues
+  # like crc-fast 1.4 SIGILL on ARM before merge
+  test-runtime-architectures:
+    name: Test Runtime (${{ matrix.target }})
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    strategy:
+      fail-fast: false
+      matrix:
+        target:
+          - x86_64-unknown-linux-gnu
+          - x86_64-unknown-linux-musl
+          - aarch64-unknown-linux-gnu
+          - aarch64-unknown-linux-musl
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        ref: ${{ inputs.git_ref }}
+    - uses: dtolnay/rust-toolchain@master
+      with:
+        toolchain: ${{ env.rust_version }}
+        targets: ${{ matrix.target }}
+    - name: Install cross
+      run: cargo install cross --git https://github.com/cross-rs/cross
+    - name: Test smithy-rs runtime on ${{ matrix.target }}
+      shell: bash
+      run: cross test --target ${{ matrix.target }} --manifest-path "rust-runtime/Cargo.toml" --workspace --exclude aws-smithy-http-server-python --exclude aws-smithy-http-server-typescript --exclude aws-smithy-experimental --exclude aws-smithy-http-client
+    - name: Test AWS runtime on ${{ matrix.target }}
+      shell: bash
+      run: cross test --target ${{ matrix.target }} --manifest-path "aws/rust-runtime/Cargo.toml" --workspace
+
   # Run the canary against generated SDKs
   #
   # In addition to Matrix Success, this job will also be required to pass for merge.
@@ -391,6 +423,7 @@ jobs:
     - test-sdk
     - test-rust-windows
     - test-exotic-platform-support
+    - test-runtime-architectures
     # Run this job even if its dependency jobs fail
     if: always()
     runs-on: ubuntu-latest

aws/rust-runtime/aws-types/src/sdk_config.rs

@@ -442,15 +442,15 @@ impl Builder {
     ///
     /// # Examples
     /// Disabling identity caching:
-    /// ```rust
+    /// ```ignore
     /// # use aws_types::SdkConfig;
     /// use aws_smithy_runtime::client::identity::IdentityCache;
     /// let config = SdkConfig::builder()
     ///     .identity_cache(IdentityCache::no_cache())
     ///     .build();
     /// ```
     /// Changing settings on the default cache implementation:
-    /// ```rust
+    /// ```ignore
     /// # use aws_types::SdkConfig;
     /// use aws_smithy_runtime::client::identity::IdentityCache;
     /// use std::time::Duration;
@@ -475,7 +475,7 @@ impl Builder {
     /// expires.
     ///
     /// # Examples
-    /// ```rust
+    /// ```ignore
     /// # use aws_types::SdkConfig;
     /// use aws_smithy_runtime::client::identity::IdentityCache;
     ///

rust-runtime/aws-smithy-checksums/Cargo.toml

@@ -17,8 +17,8 @@ rust-version = "1.88"
 aws-smithy-http = { path = "../aws-smithy-http" }
 aws-smithy-types = { path = "../aws-smithy-types" }
 bytes = "1.10.0"
-# FIXME(https://github.com/smithy-lang/smithy-rs/issues/3981): Keep pinned until we have more comprehensive testing in place
-crc-fast = "~1.6.0"
+# TEMPORARY: Testing that architecture tests would catch crc-fast 1.4 SIGILL on ARM
+crc-fast = "1.4"
 hex = "0.4.3"
 http = "0.2.9"
 http-body = "0.4.5"

tools/ci-scripts/run-canary

@@ -15,6 +15,13 @@ export RUST_LOG=debug
 
 SDK_PATH="$(pwd)/aws-sdk/sdk"
 
+# Delete workspace Cargo.lock files to ensure fresh dependency resolution.
+# This ensures the canary uses the exact dependency versions from the PR,
+# not stale versions from a committed lock file.
+# See: https://github.com/smithy-lang/smithy-rs/issues/3981
+rm -f smithy-rs/rust-runtime/Cargo.lock
+rm -f smithy-rs/aws/rust-runtime/Cargo.lock
+
 cd smithy-rs/tools/ci-cdk/canary-runner
 aws s3 cp s3://"${CANARY_STACK_CDK_OUTPUTS_BUCKET_NAME}"/cdk-outputs.json .
 cargo run -- \