Problem

The CodeQL Rust extractor reports that most of the crate fails to extract:

| Total number of Rust files that were extracted with errors   |   172 |
| Total number of Rust files that were extracted without error |    41 |

Observed in the Analyze (rust) job of the CodeQL workflow. The extraction log is full of macro-expansion failures, for example:

WARN cmd/unbounded-storage/src/fabric/error.rs:36:43: macro expansion failed for 'write'
WARN cmd/unbounded-storage/src/fabric/error.rs:38:17: macro expansion failed for 'write'
WARN cmd/unbounded-storage/src/fabric/error.rs:40:44: macro expansion failed for 'write'

These are warnings and do not fail the job, so the check reports green.

Impact

With 80% of files extracted with errors, CodeQL's Rust coverage of cmd/unbounded-storage is largely ineffective. The check passing gives more assurance than it should, which matters as the Rust surface grows (cmd/unbounded-storage, and cmd/racer alongside it).

Notes

codeql.yaml analyzes Rust with build-mode: none, so the extractor works from source without a cargo build. Macro-heavy code is exactly where that struggles. Worth checking whether a build-mode that compiles the crate improves extraction, and whether the extractor needs the workspace's feature flags (the crate has a sim feature used by its deterministic simulation harness).

Found while diagnosing an unrelated merge-queue failure; filing so it is not lost.