rust-lang/mdBook

What it measures: How tangled the control flow is — methods with many branches are hard to test and change.

Method: Cyclomatic complexity per method (1 + decision points), computed exhaustively across production source; test projects separated by convention. Deterministic.

Maturity: Documented → Verified → Prevented · effective 7.6 / 10 · rule-coverage 100% · ceiling Prevented

13 method(s) exceeded the cyclomatic complexity threshold of 15; the worst was MarkdownTreeBuilder::start_tag at 48.

+ 3 more group(s) — more in Appendix A; the complete list is findings.md.

What to do

1. Bring the 1 body over 30 down to 30 or less in Cyclomatic Complexity — start with MarkdownTreeBuilder::start_tag (cyclomatic 48). — Refactoring it lifts Cyclomatic Complexity from 7.6 to about 8.1/10.
2. Enforce Cyclomatic Complexity in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d1_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: How hard the code is for a person to follow, beyond raw branching.

Method: Cognitive complexity per method (Sonar-style nesting-penalized score), computed exhaustively over production code, excluding test projects. Deterministic.

Maturity: Documented → Verified → Prevented · effective 4.7 / 10 · rule-coverage 100% · ceiling Prevented

26 method(s) exceeded the cognitive complexity threshold of 15; the worst was mdbook_html::html::print::rewrite_links at 60.

+ 9 more group(s) — more in Appendix A; the complete list is findings.md.

What to do

1. Bring the 26 bodies over 15 down to 15 or less in Cognitive Complexity — start with mdbook_html::html::print::rewrite_links (cognitive 60), mdbook_html::html_handlebars::search::index_chapter (cognitive 53), MarkdownTreeBuilder::start_tag (cognitive 50). — This score is capped by its worst body, so a finding fixed alone moves it by almost nothing — the next one down takes its place. Refactoring these 26 together lifts Cognitive Complexity from 4.7 to about 10.0/10, projected with the scoring formula itself and assuming each lands exactly at 15.
2. Enforce Cognitive Complexity in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d2_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Over-large classes that try to do too much ("god classes").

Method: God-class detection by line and method-count thresholds per logical type (partial classes unified), filtered for generated code and registration/contract false positives. Deterministic.

Maturity: Documented → Verified → Prevented · effective 8.6 / 10 · rule-coverage 100% · ceiling Prevented

6 god class(es) detected.

What to do

1. Resolve the 2 MethodTooLong finding(s) in God Classes — start with tree.rs, toc.rs. — One of this dimension's main actionable groups (2 warning-level).
2. Resolve the 2 FileTooLong finding(s) in God Classes — start with tree.rs, book.js. — One of this dimension's main actionable groups (2 warning-level).
3. Resolve the 1 ClassTooLong finding(s) in God Classes — start with tree.rs. — One of this dimension's main actionable groups (1 warning-level).
4. Enforce God Classes in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d3_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Copy-pasted code that should be shared instead.

Method: Code duplication via token-stream sliding windows with type-aware normalization (locals masked, type names preserved), density-scored per KLoC of production code. Deterministic.

Maturity: Documented → Verified → Prevented · effective 9.8 / 10 · rule-coverage 100% · ceiling Verified

5 duplicated block group(s) detected.

What to do

1. Resolve the 2 Duplicated block (5 lines × 2) finding(s) in Code Duplication — start with static_files.rs, hbs_renderer.rs. — One of this dimension's main actionable groups (2 warning-level).
2. Resolve the 1 Duplicated block (12 lines × 2) finding(s) in Code Duplication — start with html.rs. — One of this dimension's main actionable groups (1 warning-level).
3. Resolve the 1 Duplicated block (7 lines × 2) finding(s) in Code Duplication — start with html.rs. — One of this dimension's main actionable groups (1 warning-level).
4. Enforce Code Duplication in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Verified — provenance only; does not change the score.

Detailed fixes: d4_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether volatile projects sit underneath others that depend on them (so their churn ripples upward), and whether project dependencies form cycles. A widely-depended-on but stable shared/kernel project is healthy, not penalised.

Method: Dependency cycles via elementary-DFS over real .csproj references, plus Martin instability (afferent/efferent) per project. Exhaustive over the reference graph, deterministic.

Coverage: Exhaustive · type-level: afferent/efferent coupling + cycles computed over every production type — the population is all types, not a name convention.

Maturity: Documented → Verified → Prevented · effective 8.7 / 10 · rule-coverage 100% · ceiling Prevented

12 production modules (Cargo), 0 dependency cycle(s), 0 unstable depended-on module(s). Read from the build's own module declarations; 2 module(s) off the main sequence, with abstractness counted on 10 of the 12 (the rest declare no modelled class or interface, export only macros, declare types in source no model reads, or have no source directory of their own).

What to do

1. Resolve the 2 Off the main sequence finding(s) in Coupling. — One of this dimension's main actionable groups (2 warning-level).
2. Enforce Coupling in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d5_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether a class's methods are focused on a single responsibility.

Method: LCOM4 cohesion per production class with at least two methods: connected components of methods sharing state or calls, computed syntactically. Deterministic, not a proxy.

Coverage: Exhaustive · type-level: LCOM4 cohesion computed over every production class — the population is all types, not a name convention.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Verified

0 of 18 classes have LCOM4 above 3.

✓ On the Gold path — maintain.

Detailed fixes: d6_recommendation.md.

What it measures: Whether the test suite has a healthy mix of unit / integration / end-to-end tests.

Method: Test projects classified (Unit/Integration/BDD/E2E) from compiled metadata; test methods counted exhaustively across projects with placement-agnostic disk fallback. Deterministic.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

308 test methods: 183 unit, 125 integration, 0 BDD, 0 e2e. The Rust suite contributes 308 `#[test]` function(s) across 43 file(s) declaring at least one; its unit/integration split is Cargo's own — 19 of those file(s) are integration-test targets under a crate's tests/ directory, and the rest are #[test] functions compiled into the crate they test.

✓ On the Gold path — maintain.

Detailed fixes: d9_recommendation.md.

What it measures: Whether the tests pass reliably, with no flakiness.

Method: Suite re-run N times within tiered wall-clock budgets (unit to e2e); tests failing non-deterministically across runs flagged; guarded tests retried when #if guards detected.

Maturity: Documented → Verified → Prevented · effective 0.0 / 10 · rule-coverage 100% · ceiling Verified

65 flaky across 1 measured tier(s). Rust (repository root, 43 test files): measured (65 flaky).

What to do

1. Resolve the 65 Flaky test finding(s) in Test Reliability. — One of this dimension's main actionable groups (65 issue-level).

Detailed fixes: d11_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether dependencies are current, secure, and not bloated.

Method: Manifest scan via dotnet list package across all projects; worst-signal-per-package deduction (saturating for vulnerabilities, capped-linear for deprecation/outdated) per KLoC. Exhaustive, deterministic.

Maturity: Documented → Verified → Prevented · effective 9.3 / 10 · rule-coverage 100% · ceiling Verified

14 outdated, 0 yanked direct Cargo dependencies. Only DIRECT edges are graded: a transitive crate cannot be moved past what its parent's requirement admits, so reporting one would be advice its owner cannot take. A newer release is reported only where this repository's OWN requirement already admits it, so the remedy is `cargo update` and never a manifest edit — which means a release outside the declared range is deliberately NOT charged, because a written-down constraint is a decision rather than a defect. Note that a bare requirement is a CARET, and for a 0.x crate its ceiling is the minor. Whether any crate is UNMAINTAINED is not graded — crates.io publishes no maintenance status, and release age does not stand in for one. Known CVEs in this dependency graph are D30's question, read from REDACTED there.

✓ On the Gold path — maintain.

Detailed fixes: d12_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether any secrets (keys, tokens, passwords) have leaked into the code.

Method: In-process native secret scanner (entropy plus signature patterns) across all tracked files; no external tool. A clean result is a measured 10, not no-data zero. Deterministic.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Prevented

Secret scan ran and found no leaked secrets.

✓ On the Gold path — maintain.

Detailed fixes: d13_recommendation.md.

What it measures: Whether the licenses of third-party packages are compatible with your policy.

Method: Third-party package licenses resolved from declared package metadata and checked against the configured policy (allow/deny/copyleft). Deterministic; clean = no incompatible license found at metadata depth.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Verified

0 of 250 shipped crate(s) use a banned license. Licences were resolved from crates.io over the crates a consumer compiles — this repository's REDACTED closed over its manifests' `[dependencies]` and `[build-dependencies]`. Crates it asks for ONLY under `[dev-dependencies]` are excluded: they are not compiled by anything that depends on this repository. This repository publishes itself under MPL-2.0, which is its own choice and is not judged here. ★ COVERAGE OF THIS VERDICT: it grades this repository's crate dependencies and nothing else. The repository also declares package.json, and the licences of those dependencies were NOT read by this pass — a gap in this engine's coverage, not a statement about them. So this result says the graded closure carries no banned licence; it does NOT say this repository's licensing is clear.

✓ On the Gold path — maintain.

Detailed fixes: d14_recommendation.md.

What it measures: Files that change often and are also complex — the riskiest hotspots.

Method: Per production file churn times cyclomatic complexity over a rolling window, computed from git and Roslyn/JS/Razor analysis. Exhaustive, deterministic per commit date.

Maturity: Documented → Verified → Prevented · effective 9.8 / 10 · rule-coverage 100% · ceiling Documented

Top hotspots: crates/mdbook-html/src/html/tree.rs (3×48=144)

What to do

1. Resolve the 1 Hotspot finding(s) in Churn × Complexity Hotspots — start with tree.rs. — One of this dimension's main actionable groups (1 warning-level).

Detailed fixes: d15_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether knowledge is concentrated in too few people (the "bus factor").

Method: Living knowledge per author via time-decayed commit attribution (6-month half-life, focus weighting) across largest source files. Deterministic, avoids blame's mechanical-refactor false positives.

Maturity: Documented → Verified → Prevented · effective 6.3 / 10 · rule-coverage 100% · ceiling Documented

15 source file(s) have their living knowledge concentrated in one author (≥90% of recent, decayed contribution). The largest is src/cmd/watch/poller.rs. Counted over 41 of the 63 production source files in this repository: the rest are under the ~2,400-byte size floor this dimension measures over.

What to do

1. Resolve the 1 Off-boarding risk finding(s) in Bus Factor. — One of this dimension's main actionable groups (1 recommendation-level).

Detailed fixes: d16_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Acknowledged debt left in the code — TODOs, dead code, suppressed warnings.

Method: Roslyn syntactic debt markers (suppressions/TODO/FIXME/HACK/empty-catch/commented-code/Obsolete) plus SymbolFinder dead-code analysis; weighted-debt-per-KLoC density deducted 2.0x per unit. Deterministic, exhaustive.

Maturity: Documented → Verified → Prevented · effective 9.9 / 10 · rule-coverage 100% · ceiling Prevented

8 deducted task-comment markers across 12178 LoC (0.1/KLoC) → score 9.9. Task comments only: this repository's language is read without a compiler, so D17's suppression, dead-code and commented-out-code arms did not run and this score counts fewer marker kinds than a .NET repository's would.

What to do

1. Resolve the 4 FixmeComment finding(s) in Explicit Debt — start with build.rs, poller.rs, hbs_renderer.rs. — One of this dimension's main actionable groups (4 warning-level).
2. Resolve the 4 TodoComment finding(s) in Explicit Debt — start with print.rs, serialize.rs, tokenizer.rs. — One of this dimension's main actionable groups (4 warning-level).
3. Enforce Explicit Debt in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d17_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether architecture decisions are recorded well (context, decision, consequences).

Method: Per-ADR judgment by language model at low temperature with two-pass stability; confidence is share of ADRs evaluated; enforcement-field presence detected deterministically. Advisory.

Maturity: Documented → Verified → Prevented · effective 0.0 / 10 · rule-coverage 100% · ceiling Documented

No architecture decision records were found.

What to do

1. Resolve the 1 No ADRs found finding(s) in ADR Quality. — One of this dimension's main actionable groups (1 recommendation-level).

Detailed fixes: d20_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether each project is a focused, coherent unit rather than an oversized grab-bag.

Method: Project size overshoot penalties (LoC / public-type count / namespace count, 2-of-3 flag) weighted by log magnitude. Exhaustive across projects, deterministic, LLM-independent.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

0 of 12 build units (Cargo, npm) flagged as possibly oversized/incoherent.

✓ On the Gold path — maintain.

Detailed fixes: d26_recommendation.md.

What it measures: Whether any secrets were ever committed — scanned across the full git history, not just now.

Method: Secret scan via TWO gitleaks detect passes in an isolated checkout — the full git history, then a second --no-git pass over the working tree as it stands — merged and de-duplicated by (rule, file, line); each match flagged High. Both invocations are recorded in the audit trail. Exhaustive; when the tool is absent, or when its output cannot be parsed into the expected shape, the dimension is WITHHELD as an explicit measurement gap on our side — unscored and excluded from the lens, never a hedged middling score.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

gitleaks scanned the full history AND the current working tree and found no secrets.

✓ On the Gold path — maintain.

Detailed fixes: d28_recommendation.md.

What it measures: Real static-analysis (SAST) findings — likely security bugs in the code, any language.

Method: Polyglot static analysis via semgrep across the repo using the pinned, image-baked p/security-audit + p/owasp-top-ten rulesets (no scan-time registry fetch); severity rules (ERROR/WARNING/INFO) map to a full-band severity-weighted score. Exhaustive, deterministic; degrades on parse failure.

Coverage: semgrep pattern rules over all files — exhaustive for the rule set, blind to classes of bug without a rule (clean = no rule matched).

Maturity: Documented → Verified → Prevented · effective 4.7 / 10 · rule-coverage 100% · ceiling Documented

21 finding(s): 0 critical, 13 high, 8 medium, 0 low. 11 unpinned-GitHub-Actions row(s) are reported here but scored by D36 (supply-chain provenance), which measures that posture as `pinned_actions` — one pinning decision is charged once, not once per lens. semgrep hit a parse error in 1 file(s) — `crates/mdbook-html/front-end/playground_editor/ace.js` — so no absence of findings in them is evidence of anything, and nothing in them was analysed. Fix the syntax error (or exclude the file deliberately) and re-scan to cover them. Separately, one or more rules could not re-parse an embedded snippet in 2 file(s) (e.g. a workflow `run:` block read as shell). Those files WERE scanned and their other rows are unaffected; only those rules' view of those snippets is missing.

What to do

1. Resolve the 7 REDACTED finding(s) in Static Analysis (SAST) — start with REDACTED (6), REDACTED. — One of this dimension's main actionable groups (7 warning-level).
2. Resolve the 2 REDACTED finding(s) in Static Analysis (SAST) — start with REDACTED, REDACTED. — One of this dimension's main actionable groups (2 issue-level).
3. No action in Static Analysis (SAST) — all 11 REDACTED finding(s) are reported here at file:line but scored by D36 (supply-chain provenance), so none is charged to this dimension. — One of this dimension's main actionable groups (11 issue-level, 0 of them charged here).

Detailed fixes: d29_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether any dependency has a known published vulnerability (CVE), direct or transitive, in ANY ecosystem the repository declares — Dart pub, Elixir and Erlang via Hex, Go modules, Java and Kotlin via Maven/Gradle, JavaScript/npm, .NET/NuGet, PHP/Composer, Python/PyPI, RubyGems, Rust/Cargo and Swift.

Method: Dependency-CVE scan across every ecosystem the repository declares, scored ONCE. Three sources are unioned and deduplicated by advisory identity (rule id + alias closure, CVE<->GHSA) scoped to package+version, keeping the worst severity: `osv-scanner --recursive` over osv.dev for Dart pub, Elixir/Hex (and Erlang, whose `rebar.lock` syft first converts to a CycloneDX SBOM the scanner reads, with rows attributed back to the lock), Go, Java and Kotlin via Maven/Gradle (and Scala, whose sbt build's pinned direct declarations are written into a CycloneDX SBOM the scanner reads, with rows attributed back to the build file), npm, PHP/Composer, Python/PyPI, RubyGems, Rust/Cargo and Swift; `trivy fs --scanners vuln` for npm lockfiles; and `dotnet list package --vulnerable --include-transitive` for NuGet (with per-advisory collapse of the project x target-framework fan-out), plus a DECLARED-dependency arm that resolves a published gem's gemspec against rubygems.org where no Gemfile.lock is committed. `SeverityScore(c,h,m,l, normalizer 8.0)`. NotApplicable only when NO ecosystem is readable; if any applicable ecosystem could not be scanned the findings are REPORTED and the score is withheld. Supersedes the npm and OSV arms, retired 2026-09-05.

Maturity: Documented → Verified → Prevented · effective 9.8 / 10 · rule-coverage 100% · ceiling Documented

1 finding(s): 0 critical, 0 high, 1 medium, 0 low.

What to do

1. Resolve the 1 Medium advisory (unsound) finding(s) in Dependency Vulnerabilities — start with REDACTED. — One of this dimension's main actionable groups (1 warning-level).

Detailed fixes: d30_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether anyone still has living knowledge of each file, or it has been orphaned — last understood long ago by someone now gone quiet. The sibling of the bus factor: D16 asks who owns it, D34 asks whether anyone still knows it.

Method: File orphaning as total living-knowledge decay below one focused-commit's worth within a year, computed per-file from the D16 decay model. Exhaustive, deterministic over fixed history.

Maturity: Documented → Verified → Prevented · effective 9.5 / 10 · rule-coverage 100% · ceiling Documented

2 of 41 significant source file(s) are orphaned — their living knowledge has decayed to nothing, so no one currently understands them. The largest is crates/mdbook-driver/src/builtin_preprocessors/links/take_lines.rs. Counted over 41 of the 63 production source files in this repository: the rest are under the ~2,400-byte size floor this dimension measures over.

✓ On the Gold path — maintain.

Detailed fixes: d34_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether files that change together actually belong together — pairs that repeatedly co-change in git history despite having no explicit code dependency, surfacing the hidden/logical coupling (and boundaries in the wrong place) a static scan can't see.

Method: Pairwise co-occurrence over the per-commit file sets in git history (production source only — tests and generated dropped): Degree-of-Coupling = shared ÷ min individual revisions, reported above noise floors (each file ≥10 revisions, ≥5 shared commits, ≥50% strength); sweeping commits excluded. Deterministic over fixed history.

Coverage: Population: PRODUCTION source files only — test and generated files are dropped before pairing, so a class co-changing with its own test (trivially ~100%) can't drown the real production↔production coupling. Pairs ranked by Degree-of-Coupling. A non-source file is never a coupling PARTICIPANT either: documentation, schemas, config and data files are dropped with the rest, so a code↔docs pair — a command and the reference page that restates it — is not reported however strongly the two co-change; nor is coupling that runs THROUGH a build step or config file.

Maturity: Documented → Verified → Prevented · effective 9.8 / 10 · rule-coverage 100% · ceiling Documented

Strongest change-coupling: mod.rs↔take_lines.rs 67%

What to do

1. Resolve the 1 Change coupling finding(s) in Change Coupling — start with mod.rs. — One of this dimension's main actionable groups (1 warning-level).

Detailed fixes: d35_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether the build pipeline provides supply-chain integrity — generated provenance/attestation, signed artifacts (cosign/sigstore), an SBOM, and pinned build actions. Presence of the configuration, not a runtime guarantee.

Method: Supply-chain provenance/signing read deterministically from CI/build config (.github/workflows, .gitlab-ci.yml, azure-pipelines, Jenkinsfile, .circleci) + the release surface: four signals — generated provenance/attestation (SLSA/in-toto/actions-attest), artifact signing (cosign/sigstore/gitsign), an SBOM (syft/sbom-action/*.spdx.json/*.cdx.json), and SHA-pinned build actions — scored 10·present/denom. NotApplicable without a build pipeline. Detects configuration presence, not runtime enforcement.

Maturity: Documented → Verified → Prevented · effective 0.0 / 10 · rule-coverage 100% · ceiling Documented

0/4 supply-chain integrity signals present (provenance, signing, SBOM, pinned actions).

+ 5 more group(s) — more in Appendix A; the complete list is findings.md.

What to do

1. Resolve the 1 REDACTED finding(s) in Supply-chain Provenance & Signing. — One of this dimension's main actionable groups (1 warning-level).
2. Resolve the 1 REDACTED finding(s) in Supply-chain Provenance & Signing — start with REDACTED. — One of this dimension's main actionable groups (1 warning-level).
3. Resolve the 1 REDACTED finding(s) in Supply-chain Provenance & Signing — start with REDACTED. — One of this dimension's main actionable groups (1 warning-level).

Detailed fixes: d36_recommendation.md · top locations in Appendix A, every location in findings.md.

What it measures: Whether any dependency the repository declares is published as MALICIOUS rather than merely vulnerable — a package that is an attacker's work, in any ecosystem osv-scanner reads. Scored apart from D30 because the answer is binary: there is no safe version to upgrade to, and the fix is to remove the package and rotate every credential it could have read.

Method: The same dependency scan D30 reads, partitioned on the scanner's own classification rather than rescanned: a row is MALICIOUS when its id is in the `MAL-` space (the ossf/malicious-packages feed) OR its `database_specific.cwe_ids` carries `CWE-506` ("Embedded Malicious Code"). Both channels are structural; the summary text is deliberately NOT read, because a malicious-package record whose summary says only "Critical severity vulnerability" is a real shape ([GHSA redacted]) and a text matcher misses it. Scored BINARY: any surviving row is 0, whatever its severity and however many CVEs sit beside it — a hostile dependency is not a quantity. Applicability and degradation are D30's: NotApplicable only when no ecosystem is readable, and an unscannable ecosystem degrades rather than reading clean. SCORED, not informational.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

No dependency in any ecosystem this repository declares is published as malicious.

✓ On the Gold path — maintain.

Detailed fixes: d43_recommendation.md.

What it measures: Whether anyone still ships security patches for the platform this repository RUNS ON — the runtime it pins and the framework majors its own constraints hold it to. Separate from D12 because the question differs: a current Django on an end-of-life Python is perfectly up to date and completely unsupported, and the fix is a migration rather than a version bump. What the repository says it merely SUPPORTS is never charged.

Method: End-of-life PLATFORM read from the repository's own declarations and graded against a FROZEN, dated table of vendor support dates — no network, no feed, no API, so this dimension answers identically inside a closed scan fence. Two subjects: a RUNTIME the project pins (a single or all-end-of-life TargetFramework, a .nvmrc or .python-version, a requires-python CAP) and a FRAMEWORK major a dependency constraint cannot move off (a caret, tilde or exact version; `vue@^2.7.16` pins Vue 2). A FLOOR is deliberately never charged — `requires-python = ">=3.8"` states what a package SUPPORTS, not what it runs on — and a multi-target project is charged only when EVERY target is out of support. Runtime 4.0/product capped 8.0, framework 1.5 capped 4.5. The table is safe to freeze because a statement about support that ended in the past cannot become false: it loses recall as it ages, never precision, and a test asserts every entry predates the freeze date. Disjoint from D31 (a container image's OS layer) and D29 (the toolchain a CI workflow installs). Abstains when the repository declares no platform this pass reads — never scores it clean.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

0 end-of-life runtime(s) and 0 end-of-life framework(s), read from 1 platform declaration(s) and 2 dependency declaration(s). This dimension reads what the repository says about ITSELF — a pinned target framework, a version file, a capped requires-python, a Rust toolchain pin, a framework major a constraint cannot move off. A FLOOR is deliberately never charged: `requires-python = ">=3.8"` states what the package SUPPORTS, not what it runs on, and a well-maintained library declares exactly that while running its own CI on a current release. The end-of-life facts are FROZEN and dated, so this dimension needs no network and answers identically inside a closed scan fence; as the table ages it loses recall and never precision, because a statement about support that ended in the past cannot become false. The OS layer of a container image is D31's question and the toolchain a CI workflow installs is D29's; this row is neither.

✓ On the Gold path — maintain.

Detailed fixes: d44_recommendation.md.

Other · Accessibility — Whether non-text content carries a text alternative — img/area/input[type=image] have alt, a meaningful svg has a title or aria-label, video has a captions track, and object/embed/canvas have a name or fallback content. Static markup readiness, not a WCAG conformance claim.

Method: Static markup-model scan: every img/area/input[type=image] checked for alt, svg[role=img] for a title/aria-label, video for a captions <track>. Components skipped, spreads suppressed. Deterministic, hard fact per element.

Coverage: Population: image/media elements — img, area, input[type=image], svg, video, object, embed, canvas — across the PARSED MARKUP files only (.html/.htm/.cshtml/.razor/.vue/.svelte/.jsx/.tsx); components, hidden subtrees and dynamic-attribute elements are skipped. Markup built in script — tagged-template (html`…`) UIs and hyperscript DOM factories — is NOT read by any producer, so it contributes no element to this population; where such a frontend is present the card discloses it as an analyzer gap rather than scoring around it.

Other · Accessibility — Whether form controls have a programmatic label (an associated label, aria-label or aria-labelledby), buttons have text, links have an accessible name, a click handler on a plain element names the control it declares, fieldsets have a non-empty legend, known UI-library field components carry a label prop, and a placeholder isn't used as the only label. Static markup readiness, not a WCAG conformance claim.

Method: Static markup-model scan: inputs/selects/textareas checked for an associated label[for]/wrapping label/aria-label/aria-labelledby (per document), buttons for accessible text, fieldsets for a legend; placeholder-only labelling flagged. Deterministic, hard fact per control.

Coverage: Population: form controls, buttons, links, fieldsets and known UI-library field components in the PARSED MARKUP files only (.html/.htm/.cshtml/.razor/.vue/.svelte/.jsx/.tsx); components, hidden subtrees and spread/dynamic-attribute elements are skipped, so a control whose label arrives through a spread or a runtime expression is deliberately not judged. Markup built in script — tagged-template (html`…`) UIs and hyperscript DOM factories — is not read at all.

Other · Accessibility — Whether pages declare a language (well-formed BCP-47) and a non-empty title, expose exactly one main landmark and a sane heading order with non-empty headings, keep zoom enabled, title their iframes, give data tables header cells, and avoid meta-refresh. Static markup readiness, not a WCAG conformance claim.

Method: Static markup-model scan: html lang, document <title>, a main landmark and heading order on full documents only, plus zoom-disabling viewports, untitled iframes and meta-refresh anywhere. Deterministic, per structural checkpoint.

Coverage: Population: the PARSED MARKUP documents (.html/.htm/.cshtml/.razor/.vue/.svelte/.jsx/.tsx). The page-level checks — lang, title, single main landmark — fire ONCE PER FULL DOCUMENT (an <html> root) and never on a partial or component fragment, so a repo of fragments is assessed only on the per-element checks (heading order, table headers, iframe titles, meta-refresh, zoom). Markup built in script — tagged-template (html`…`) UIs and hyperscript DOM factories — is not read at all.

• An iframe with no title (or an empty one) is announced only as "frame". Add a non-empty title describing its content, or an aria-label. — REDACTED:135
• No <main> (or role="main") means no "skip to content" target and a weaker landmark map. Wrap the primary content in <main>. (×2) — REDACTED:2, crates/mdbook-html/front-end/templates/toc.html.hbs:2
• A <table> with data cells but no <th> gives assistive technology no way to associate cells with their headers. Mark the header row/column cells as <th> (with a scope). — crates/mdbook-html/front-end/templates/toc.js.hbs:200

What to do

• Declare <html lang>, a document <title> and a <main> landmark, keep headings in order, leave zoom enabled, title iframes and drop meta-refresh.

Other · Accessibility — Whether interactive behaviour is keyboard-reachable — no click handler on a non-interactive element lacking a role, tabindex and key handler, no element the repo's own CSS styles `cursor: pointer` without giving it any of the three, no unfocusable element whose only binding is a mouse enter/leave pair or a double-click, no positive tabindex, no href-less anchor, no placeholder-href (#/javascript) link acting as a button. Static markup readiness, not a WCAG conformance claim.

Method: Static markup-model scan: click handlers on non-interactive elements lacking role+tabindex+key handler, positive tabindex values, and href-less anchors. Components skipped, spreads suppressed. Deterministic, hard fact per element.

Coverage: Population: elements that pose a keyboard-semantics question, in the PARSED MARKUP files only (.html/.htm/.cshtml/.razor/.vue/.svelte/.jsx/.tsx) — a non-natively-interactive element carrying a click handler, a double-click or hover enter/leave binding, a pointer-only gesture on a tabindex="0" element, or `cursor: pointer` from the repo's own CSS; an href-less or placeholder-href (#, javascript:) anchor; and any element with a positive tabindex. Natively interactive elements used correctly (<button>, <a href>, form controls) are NOT in the population — there is nothing to judge — so a page of nothing but correct controls gives AC4 nothing to measure. Keyboard reachability is judged from the markup, never from a rendered page. ★ An interactive element declared in a tagged-template (html`…`) or hyperscript frontend is NOT in this population — no producer reads either — so an empty population is reported as an analyzer gap, never as "this repository has no interactive elements".

• The repo's own CSS styles .menu-title with `cursor: pointer`, so this <h1> is a control — but it has no role, no tabindex="0" and no key handler, so it can only be reached with a mouse. Use a <button>, or add role + tabindex="0" + a key handler. — REDACTED:168

What to do

• Make custom controls keyboard-operable (role + tabindex + key handler), drop positive tabindex, and give anchors a real href.

Other · Accessibility — Whether ARIA is used correctly — valid non-abstract roles, the ARIA state a role requires, valid (non-misspelled) aria-* attribute names, in-enum values for token-typed aria-* attributes, and no aria-hidden on (or wrapping) a focusable element. Static markup readiness, not a WCAG conformance claim.

Method: Static markup-model scan: role values checked against the WAI-ARIA role set (abstract/invalid flagged), required ARIA state for a role, and aria-hidden on a focusable element. Deterministic, role/attribute level.

Coverage: Population: elements in the PARSED MARKUP files (.html/.htm/.cshtml/.razor/.vue/.svelte/.jsx/.tsx) that carry a role or an aria-* attribute; roles and token values are checked against the ARIA enums exhaustively within that set. An expression-valued (dynamic) role or aria-* value is skipped rather than guessed, and markup built in script — tagged-template (html`…`) UIs and hyperscript DOM factories — is not read at all.

Other · Accessibility — Whether focus outlines aren't removed without a replacement, motion respects prefers-reduced-motion, and literal CSS colour pairs meet contrast — PARTIAL: inline styles, in-repo <style> blocks, in-repo .css files, var() tokens, Tailwind neutral utilities and CSS-in-JS literals are read (hex/rgb/hsl/named), never computed/runtime/external-CDN colour. Static markup readiness, not a WCAG conformance claim.

Method: Static markup/CSS scan: inline outline:none/0, literal inline colour/background contrast against the 4.5:1 AA floor, and <style>-block animation without a prefers-reduced-motion guard. Deterministic but PARTIAL — only inline styles and in-repo CSS literals are visible.

Coverage: Population: styled elements in the PARSED MARKUP files (.html/.htm/.cshtml/.razor/.vue/.svelte/.jsx/.tsx), plus in-repo <style> blocks, in-repo .css files and CSS-in-JS literals. Colour contrast is computed from LITERAL colour pairs only (hex/rgb/hsl/named, including var() tokens and Tailwind neutral utilities) — computed, runtime-themed and external-CDN colour is never resolved, so this is a partial read of contrast by construction. Markup built in script — tagged-template (html`…`) UIs and hyperscript DOM factories — is not read at all.

• `.page` sets the outline to none/0 and no visible :focus / :focus-visible style for that element replaces it in this stylesheet, so a keyboard user cannot see where focus is. Draw a focus ring (outline, box-shadow or border) under :focus-visible. — crates/mdbook-html/front-end/css/general.css:84
• `#fa-spin` moves (`animation: rotating 2s linear infinite`) and nothing reads prefers-reduced-motion for it — no @media (prefers-reduced-motion) rule for this element, no reset this project loads — so a motion-sensitive user cannot turn it off (WCAG 2.3.3). Declare it under @media (prefers-reduced-motion: no-preference), or neutralise it under reduce. — crates/mdbook-html/front-end/css/chrome.css:371
• `html:not(.sidebar-resizing) .sidebar` moves (`transition: transform 0.3s`) and nothing reads prefers-reduced-motion for it — no @media (prefers-reduced-motion) rule for this element, no reset this project loads — so a motion-sensitive user cannot turn it off (WCAG 2.3.3). Declare it under @media (prefers-reduced-motion: no-preference), or neutralise it under reduce. — crates/mdbook-html/front-end/css/chrome.css:487
• `.chapter-fold-toggle div` moves (`transition: transform 0.5s`) and nothing reads prefers-reduced-motion for it — no @media (prefers-reduced-motion) rule for this element, no reset this project loads — so a motion-sensitive user cannot turn it off (WCAG 2.3.3). Declare it under @media (prefers-reduced-motion: no-preference), or neutralise it under reduce. — crates/mdbook-html/front-end/css/chrome.css:638
• `html:not(.js) .page-wrapper` moves (`transition: margin-left 0.3s ease, transform 0.3s ease`) and nothing reads prefers-reduced-motion for it — no @media (prefers-reduced-motion) rule for this element, no reset this project loads — so a motion-sensitive user cannot turn it off (WCAG 2.3.3). Declare it under @media (prefers-reduced-motion: no-preference), or neutralise it under reduce. — crates/mdbook-html/front-end/css/general.css:94
• `[dir=rtl]:not(.js) .page-wrapper` moves (`transition: margin-right 0.3s ease, transform 0.3s ease`) and nothing reads prefers-reduced-motion for it — no @media (prefers-reduced-motion) rule for this element, no reset this project loads — so a motion-sensitive user cannot turn it off (WCAG 2.3.3). Declare it under @media (prefers-reduced-motion: no-preference), or neutralise it under reduce. — crates/mdbook-html/front-end/css/general.css:98

What to do

• Keep a visible focus style (don't remove the outline without a replacement), guard animation with prefers-reduced-motion, and raise low-contrast colour pairs to at least 4.5:1.

Other · Accessibility — Whether accessibility is ENFORCED in the toolchain — an accessibility checker configured over the markup (an a11y lint rule set, e.g. eslint-plugin-jsx-a11y or vuejs-accessibility where the project lints JavaScript) and an automated accessibility assertion wired into tests or CI (axe/pa11y/Lighthouse or an equivalent) — on the Documented→Verified→Prevented ladder.

Method: Repo config/CI scan: an accessibility checker configured over the markup (an a11y lint rule set such as eslint-plugin-jsx-a11y / vuejs-accessibility where JavaScript is linted) and an automated accessibility assertion in tests or CI (axe/pa11y/Lighthouse or equivalent), graded on the Documented→Verified→Prevented rungs. Deterministic, presence/rung detection.

Coverage: Population: the repository's own tooling configuration — lint config, test and CI files — NOT the markup. It is read for a configured accessibility checker and an automated accessibility assertion (axe/pa11y/Lighthouse, or a native-toolkit equivalent), and it credits an INVOCATION, never a mention: a licence filename, an import comment or a doc reference earns no rung. Enforcement configured entirely outside the repository leaves no evidence here and cannot be credited.

• No accessibility enforcement found — no a11y linter (an accessibility check that can read your UI — no component framework was detected and your pages are rendered by server-side templates, which neither the JSX/Vue ESLint plugins nor the HTML-template linters can parse; run axe/pa11y over the rendered pages, or assert the accessibility invariants over that rendered HTML in the test suite you already have) and no axe/pa11y/Lighthouse in tests or CI. Start by running that check over your rendered pages in CI. What was searched, so you can tell an absence from a miss: the 6 markup file(s) this pass actually assessed, the linter configuration checked in beside them, and this repository's test and CI files — matched by name against the accessibility checkers this dimension carries. An audit run outside the repository, a hosted scanner, or a check whose name is not one of those, is not seen here.

What to do

• Enforce accessibility in the toolchain: add an accessibility check that can read your UI — no component framework was detected and your pages are rendered by server-side templates, which neither the JSX/Vue ESLint plugins nor the HTML-template linters can parse; run axe/pa11y over the rendered pages, or assert the accessibility invariants over that rendered HTML in the test suite you already have, then assert with your test runner's axe binding (jest-axe, vitest-axe, cypress-axe or @axe-core/playwright) in tests, then gate axe/pa11y/Lighthouse in CI.

Other · Architecture — How the codebase splits by code ROLE — domain, application, infrastructure, test, generated. The significance map behind the knowledge/coupling weighting, and a DDD signal in its own right: a thin domain core under fat infrastructure is the anemic-domain smell, quantified. How each file's role is decided, because the split is only as good as that: a generated name or a build-output tree makes it Generated, a test project makes it Test, and otherwise the file's NAMESPACE and PATH words are matched against fixed vocabularies in a fixed ORDER — domain, then infrastructure, then application — so a file whose words hit two layers is counted under the earlier one. A production file matching none of them counts as application, so that share reads 'application or unclassified' rather than a measured application layer. Roles come from naming convention, never from what the code does. On this repository the split was taken from the source tree on disk rather than from a loaded .NET workspace, so a file's role is decided by its PATH segments alone — no declared namespace was available to add to the evidence — and generated output is excluded from the census entirely rather than counted as a generated share.

Method: Roslyn line-count by code ROLE: every source file classified Domain/Application/Infrastructure/Test/Generated by namespace + path convention (the shared CodeRoleClassifier), then significant lines summed per role. Deterministic; the advisory score is the business-logic (domain+application) share of production code.

Coverage: Population: ALL source files, each bucketed into ONE of five roles (Domain/Application/Infrastructure/Test/Generated) by namespace + path convention — a file whose layer isn't named in the convention falls to Application (the neutral default), and the split is line-count, not semantic depth or business value.

What to do

• The domain core is a small share of production code, but most of the rest matched no layer vocabulary at all — so this is not yet an anemic-domain finding. The namespace/path convention could not place that code, which makes the composition above a statement about the naming, not about the design. Name the layers (or check that the repository's conventions differ from the ones this check knows) before reading a thin domain into it.

Other · Architecture — Whether the project-reference graph is acyclic (cycles block independent build/deploy and signal eroding boundaries).

Method: Project reference cycles via elementary-DFS over real .csproj references, using the engine shared with D5/D7; cyclic versus acyclic. Exhaustive, deterministic.

Other · Architecture — Whether dependencies point inward (Domain ← Application ← Infrastructure/Web) — the clean-architecture dependency rule, checked across the project graph.

Method: Layer violations by name-segment inference (Domain/Core to Application to Infrastructure/Web) over the project-reference graph. Exhaustive over all projects, deterministic.

Other · Architecture — Whether read (query) handlers stay side-effect-free — a query that writes persistent state or raises events breaks CQS and makes reads unsafe to retry, cache, or route to a read replica.

Method: Roslyn scan: CQRS handlers classified query-vs-command by interface (IQueryHandler/ICommandHandler/IRequestHandler<TQuery,TResult>) and name convention (*Query/Get*/Find* vs *Command); each query handler's body checked for persistent-state writes (SaveChanges/repository Add-Update) or event publishes by resolved invocation. Deterministic, type-level, exhaustive over the detected handlers.

Coverage: Population: CQRS handlers identified by IQueryHandler/ICommandHandler/IRequestHandler interface + *Query/Get*/Find*/*Command NAME convention; query purity then checked exhaustively within that set — a query handler using neither convention is invisible, and mutation is a resolved persistence/publish CALL, not full dataflow.

Maturity · Maturity — Whether the repo and its projects have a README, and whether it's substantive and current.

Method: Filesystem scan: README presence, word count, and headings for depth; git history for staleness. Exhaustive across root and project dirs, deterministic.

• The root README is 98 words, against a bar of 120. Of the three newcomer-critical sections this check looks for by heading, it found no a build/run or getting-started section, no a testing section, no an architecture or project-map section. Sections are matched on HEADING text only, so material written under a heading this check does not recognise — or with no heading at all — is not seen and this row may understate what the document covers.

What to do

• Expand the README with getting-started, architecture overview and a project map.
• Add a build/run (quick start) section to the root README — the first thing a newcomer needs.
• Explain in the README how to run the tests. Add a section called Testing to the README in the repository's top folder, saying how to run the test suite.
• Add an 'Architecture' / 'How it works' section to the root README — the high-level shape.
• Add a README to the 3 of 12 project(s) that lack one — worth up to 0.5 pts.

Maturity · Maturity — Whether key decisions (ADRs) and the high-level shape (C4/diagrams) are written down.

Method: Filesystem scan: ADR folder/naming conventions or content, plus Mermaid/PlantUML/C4/architecture.md discovery. Exhaustive, deterministic.

• No Architecture Decision Records found — no conventional ADR directory, no numbered `NNNN-title` documents in any markup this check reads, and nothing ADR-shaped by content. Design rationale recorded elsewhere (a design-notes tree, a mailing list, pull-request discussion) is not visible to this check and is not re-findable per decision, so a future maintainer cannot ask why one choice was made and get an answer.
• No C4/Structurizr/PlantUML/Mermaid/Graphviz/D2 diagram, no drawn diagram named for the architecture, no file named `architecture` or `design` in any markup this check reads, and nothing in the README, docs or contributor guides that announces the shape — no `## Architecture` heading, no "architecture overview"/"high-level design" phrasing, no "the architecture is …" introduction, no guided code tour. A shape laid out in prose that never names itself as the architecture is not visible to this check, and neither is one kept outside the repository, so this row reports the absence of a re-findable shape document — not evidence that nobody wrote the shape down.

What to do

• Record your significant design decisions. Write one short document per decision, giving its date, the situation, the decision and its consequences, and keep them together with your other design documents. A docs/adr folder with each file named by number and title is the easiest place to find them.
• Add a C4 context/container diagram (Structurizr, PlantUML or Mermaid) or an architecture.md overview.

Maturity · Maturity — Whether the repo is organised deliberately — src/test separation and consistent project naming.

Method: Filesystem scan: src/test folder separation and namespace-prefix consistency (majority RootNamespace agreement). Exhaustive across projects, deterministic.

Maturity · Maturity — Whether the README actually describes the code that exists (LLM-judged, advisory).

Method: Judged by language model at low temperature: README accuracy versus actual projects, within a disclosed tolerance. Advisory, not a measured number.

Readiness · Readiness — Whether an automated pipeline builds and tests every change.

Method: Filesystem scan: CI workflow files (.github/workflows, .gitlab-ci.yml, etc.) for build and test stages. Exhaustive, deterministic.

Readiness · Readiness — For a library: a deliberate (small) public API surface and explicit semantic versioning so consumers can depend on it safely.

Method: Roslyn scan: public API surface area and semantic-versioning markers (SemVer attributes, changelog entries) for libraries; off .NET, a library is the ecosystem's publication act (an npm package that is not private and names an entry point, a PyPI distribution with a build system, a Rust library crate, a Maven/Gradle module that publishes, a Go module with no package main, a gemspec, a Composer library, a SwiftPM library product, a pub.dev or Hex package), its surface is the share of types the language model records as public (Rust, Swift, Java, Kotlin, Go, Dart; not measured where the model records no type visibility or, as in TypeScript, only module-level export), and its version is read from the manifest, a semver CHANGELOG, release tooling or semver git tags. Exhaustive, deterministic.

Readiness · Readiness — Whether the code is diagnosable in production — structured logging, tracing/metrics, health checks.

Method: Filesystem/Roslyn scan: structured-logging frameworks (Serilog, NLog), OpenTelemetry, and health-check endpoint patterns. Exhaustive, deterministic.

• Only 6/9 runnable modules use logging (modules with no entry point or server are excluded — they are libraries a runnable module hosts). Silent: `crates/xtask`, `guide/guide-helper`, `guide/src/for_developers/mdbook-wordcount`.

What to do

• Extend structured logging to the remaining runnable modules so everything you run is diagnosable in production.
• Consider OpenTelemetry tracing/metrics (@opentelemetry/sdk-node) and a health-check endpoint (@godaddy/terminus or a /health route) for operability.

Readiness · Readiness — Whether SAST, secret/dependency scanning and performance benchmarking are wired in (presence, not runtime).

Method: Filesystem scan: SAST configuration, dependency-update automation, secret scanning, and a benchmark harness or benchmark step — in this repository's own ecosystem. Exhaustive, deterministic.

What to do

• Enable Dependabot/Renovate or a dependency-review gate.
• Add gitleaks/trufflehog in CI to block PRs that introduce committed secrets.

Readiness · Readiness — Whether releases are automated and safely reversible (probes, rolling updates, approval gates) — from manifests/pipeline files, not the live environment.

Method: Filesystem scan: deployment manifests/IaC (K8s YAML, Helm, Terraform) for rolling updates, probes, approval gates, migration hooks. Exhaustive, deterministic.

Readiness · Readiness — Whether releases are traceable — a maintained changelog and explicit version stamping.

Method: Filesystem scan: changelog file presence and version tags in csproj or git tags. Exhaustive, deterministic.

Readiness · Performance — Whether asynchronous code stays responsive — it avoids sync-over-async blocking (a .NET .Wait()/.GetAwaiter().GetResult(), a time.sleep or blocking HTTP call inside a Python coroutine, a *Sync call inside an async JavaScript function, block_on inside a Rust async fn, runBlocking inside a Kotlin suspend function, block() inside a Reactor publisher) that stalls a thread or event loop and risks deadlock, and, where the code is a reusable library on .NET, awaits with ConfigureAwait(false) so it never captures and stalls its caller's context.

Method: Production-source scan: sync-over-async blocking counted everywhere — .Wait()/.GetAwaiter().GetResult() in .NET; off .NET, read from the language model, a blocking call inside an async function (Python, TS/JS, Rust, Kotlin, Swift, Dart) or inside a Java method returning a Reactor Mono/Flux or a Scala method returning a Future or effect — and, for a .NET library with ≥5 awaits, the share of awaits using ConfigureAwait(false). Deterministic, syntax/text detection.

Other · Security — Read from this repository's Rust source: cryptographic hygiene (weak hash or cipher, key material fixed in the source) and outbound TLS (certificate validation, protocol version) — facts about code that hold whether or not it serves anything itself. Markup this repository SHIPS is scored for third-party script integrity whether or not the repository serves it itself, since a page handed to a consumer runs in that consumer’s origin. This repository serves HTTP itself (`axum::serve(` (src/cmd/serve.rs:177)), so its Rust source was also read for the server controls: TLS served or HSTS set, security response headers, cookie flags and inbound validation — each credited where its Rust spelling appears in production source, not proven on every route. A Rocket 0.5 application is credited the headers Rocket's default `Shield` sends unless it attaches its own, and its cookie jar's SameSite=Strict default; a session middleware its default cookie flags.

Method: Roslyn plus filesystem scan: HSTS/security headers, secure cookies, input validation, middleware order, weak crypto (MD5/SHA1/DES); HTTPS-metadata context-aware. On a repository with no .NET source it reads JavaScript/TypeScript, Dart, Ruby, Scala, Rust or Elixir source itself (test, vendored, generated and minified paths not) for the arms that hold whether or not the code serves HTTP: a weak hash or cipher, key material fixed in the source, a TLS client that accepts any certificate, and (JavaScript/TypeScript, Ruby, Scala, Rust and Elixir) an obsolete TLS version; the server controls are not assessed there, and a Dart, Ruby, Scala, Rust or Elixir repository that serves no HTTP of its own is N/A on them. Deterministic.

• `https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML` is executed by this page with no Subresource Integrity. Whoever can answer that request — the CDN, anyone who compromises it, anyone on the network path — runs arbitrary script in this page's origin, with its session. — REDACTED:53
• This repository starts an HTTP server and nothing in its Rust source or committed `Rocket.toml` secures the transport: no TLS served (actix-web `bind_rustls`/`bind_openssl`, axum-server `bind_rustls` with a `RustlsConfig`, tonic `ServerTlsConfig`, a `TlsAcceptor`, Rocket's `[default.tls]`), no `Strict-Transport-Security` header, no `X-Forwarded-Proto` read from a TLS-terminating proxy — so its traffic may cross the network in clear text. (−2.0 on this card.) The server: `axum::serve(` (src/cmd/serve.rs:177).
• None of the 11 security response headers the OWASP Secure Headers Project recommends (Content-Security-Policy, Strict-Transport-Security, X-Content-Type-Options, X-Frame-Options, …) is set on a response this repository's Rust server sends — defense in depth, even when a proxy could set them. (−2.0 on this card.) The server: `axum::serve(` (src/cmd/serve.rs:177).
• No handler of this repository's Rust server answers 400, 413 or 422 (`StatusCode::BAD_REQUEST`, `HttpResponse::BadRequest()`, `Status::BadRequest`, tonic `Status::invalid_argument`), and nothing declares validation — no `validator`/`garde` derive, no body limit (`DefaultBodyLimit::max`, `RequestBodyLimitLayer`, `JsonConfig::default().limit(…)`, Rocket `Limits`) — nothing shows inbound requests being checked, and refused, before a handler acts on them. A check that answers its failure with 200 and an error body is not seen. (−2.0 on this card.) The server: `axum::serve(` (src/cmd/serve.rs:177).

What to do

• Pin third-party scripts and verify them: name an exact version in the URL and add an `integrity="sha384-…"` hash alongside `crossorigin="anonymous"` (both are required — an integrity hash on a cross-origin script without `crossorigin` is not evaluated, it blocks the script). Where the vendor ships a continuously-updated loader and publishes no stable hash (tag managers, analytics, chat widgets), Subresource Integrity is not available: constrain it instead with a `Content-Security-Policy` that names the exact origins allowed to execute, and drop the script from the pages that do not need it. Where the page is shipped inside a package that others host, prefer vendoring the asset and serving it from the app’s own origin, so no consumer inherits a third-party dependency they did not choose.
• Secure the server's transport: serve TLS itself (`HttpServer::bind_rustls_0_23(addr, config)` in actix-web, `axum_server::bind_rustls(addr, RustlsConfig::from_pem_file(…))`, tonic's `Server::builder().tls_config(ServerTlsConfig::new().identity(…))`, Rocket's `[default.tls]`), or run it behind a TLS-terminating proxy and check `X-Forwarded-Proto`; send `Strict-Transport-Security` once it is HTTPS-only.
• Set security response headers on what the server sends — actix-web's `DefaultHeaders::new().add((header::X_CONTENT_TYPE_OPTIONS, "nosniff"))`, tower-http's `SetResponseHeaderLayer::overriding(…)` on an axum router, or keep Rocket's default `Shield` — with `Content-Security-Policy`, `X-Content-Type-Options` and a frame policy on every response.
• Validate what the server reads from a request — path, query, headers, body size and shape — and answer what fails with 400 (413 for an oversized body) before a handler acts on it: derive `validator::Validate` (or `garde::Validate`) on the request types and reject with `StatusCode::BAD_REQUEST`, and cap bodies with `DefaultBodyLimit::max`/`RequestBodyLimitLayer` or actix's `JsonConfig::default().limit(…)`.

Other · Code Health — Whether the code avoids sync-over-async (deadlock-prone blocking on tasks) and async void.

Method: Roslyn syntax scan: async methods scanned for .Wait()/.GetAwaiter().GetResult() and async-void outside event handlers. Deterministic, hard fact per invocation.

Other · Code Health — Whether any branch is dead by construction — a switch arm whose label can never equal a case-normalised subject, or an `else if` whose predicate the arm above has already swallowed.

Method: Roslyn syntax + semantics: switch labels compared against the subject's own case normaliser, and if/else-if chains checked for a literal an earlier arm's containment test already swallows. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a child process that has BOTH standard streams redirected drains both — reading one to the end while the other is never read deadlocks once the child fills the unread pipe.

Method: Roslyn syntax + semantics: ProcessStartInfo launches with both streams redirected, checked for a drain of each stream across the enclosing type. On a repository with no .NET source it reads JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not) with the same rule: a `spawn` imported from `child_process` whose stdout and stderr are both pipes (no options, no `stdio`, or `stdio` of `'pipe'`), bound to a local that never leaves its scope, where exactly one of the two streams is read, the other never, and the child’s `close`/`exit` (or the read stream’s end) is awaited; a shell redirect in the call’s arguments or a `kill` of the child suppresses it. The same rule reads Python’s `subprocess.Popen`, Dart’s `Process.start`, Ruby’s `Open3.popen3`, and Scala’s JDK process starts (`new ProcessBuilder(…).start()` with no `redirectErrorStream`/`redirectError`/`redirectOutput`/`inheritIO`, `Runtime.getRuntime.exec`) where one of `getInputStream`/`getErrorStream` is read and the other never while `waitFor()` is called or the read stream is read to its end. Deterministic, provable per finding. Advisory.

Other · Security — Whether a hand-rolled public/private IP check can be walked past — a method that unwraps IPv4-mapped IPv6 but returns the opposite verdict for the same host written as IPv4-compatible, 6to4 or NAT64.

Method: Roslyn syntax + semantics: methods that unwrap IPv4-mapped IPv6 and hand-roll IPv4 range carve-outs, checked for whether the IPv6 branch also accounts for the IPv4-compatible, 6to4 and NAT64 embeddings. Deterministic, provable per finding. Advisory.

Other · Security — Whether a length read out of the stream being parsed is bounded before it is allocated or read — an unchecked count taken from the input lets the input choose the allocation.

Method: Roslyn syntax + semantics: integer lengths read from a BinaryReader and spent on a bulk read or an array allocation, checked for any comparison or bounding call on the value anywhere in the method. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a loop that shortens a string until it fits a length budget has a floor — one with none grinds the value down to the empty string, or past it into a negative-length `Substring`.

Method: Roslyn syntax + semantics: while/do loops whose body's only effect on a string is to drop its last character, checked for whether anything — a direct comparison on the length, a body guard, a break — bounds that length below. On a repository with no .NET source it reads JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not) with the same rule: a `while`/`do` loop whose body’s one assignment to a value is `x = x.slice(0, -1)` or `x = x.slice|substring|substr(0, x.length - 1)`, driven by a condition that reads `x.length` only as a term of a larger expression — never compared directly, never tested for truthiness, and with no other read of `x` — and whose body has no `break`, `return`, `throw` or `if` naming `x`. Deterministic, provable per finding. Advisory.

Other · Security — Whether a walk that recurses through a JSON/XML tree handed in by its caller bounds how deep it will go — an uncapped walk lets the document's nesting choose the stack depth, and the resulting StackOverflowException cannot be caught.

Method: Roslyn syntax + semantics: methods that take a JSON/XML document node and call themselves with a child of it, reachable from an externally-callable member of the same type that accepts a document, checked for any depth parameter, descent counter or threaded arithmetic anywhere in the walk. On a repository with no .NET source it reads TypeScript off the engine’s own token stream (test, vendored, generated and minified paths and `.d.ts` not) with the same rule: a function or method with a parameter typed as a document value — `unknown`, `any`, `object`, `Record<string, unknown|any>`, a JSON alias (`JsonValue`, `JSONObject`, …) or a DOM node global the file does not rebind — that calls itself (bare, or through `this` for a method, or hands itself to a call over the value as in `value.map(walk)`) with something it took out of that value and never through an ancestor accessor such as `closest()` or `parentElement`, that is exported or reached from an exported function (a public method of the same exported class) taking such a value, and that names no depth, level, nesting, recursion, remaining or budget anywhere and threads no `+`/`-` arithmetic through a self-call. Plain JavaScript is not read: with no annotation nothing tells a parsed document from a tree the code built itself. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a type's disposal matches what it OWNS — releasing what it created, leaving alone what it was handed, and not declaring a finalizer for state that has nothing unmanaged to finalize.

Method: Roslyn syntax + semantics: every assignment to a disposable field is read to decide whether the type CREATED the value or was handed it, and the type's disposal is checked against that answer — an injected interface it disposes, a value it constructed and never releases, a finalizer on a type holding nothing unmanaged, and a disposable local whose every reference is a plain member read. A value handed to a container that disposes its contents (a parent control's `Controls` collection, a component `IContainer`) is released by that container and is not reported; generated code is out of population. On a repository with no .NET source the same ownership questions are read in JavaScript/TypeScript off the engine’s own token stream (test, vendored, generated and minified paths not): a class declaring `dispose()`, `[Symbol.dispose]()` or `[Symbol.asyncDispose]()` that disposes a field it was handed through a constructor parameter typed as a repository interface or resolved by a dependency-injection container; that assigns a field only ever from `new X(…)` of a disposable class and neither releases it anywhere in the class nor names it in its disposal member or a method that member calls, nor hands it to anything else; and a `const`/`let` local built from literals only whose every reference opens a statement operating on a non-release member of it. A class is disposable when every repository declaration of its name declares or inherits a disposal member, or when it is a documented library disposable (`vscode` EventEmitter, CancellationTokenSource and Disposable; three.js geometries, materials, textures, render targets, renderers, controls and composers). The finalizer arm has no JavaScript counterpart: a class cannot declare one. Dart is read for the owned-and-never-released arm: a Flutter `State` (or a class declaring `dispose()`/`close()`) whose library-private field is written only with direct creations of a framework controller, `FocusNode`, `StreamController` or periodic `Timer` (or a `.listen(…)` into a field declared `StreamSubscription`), which nothing in the class or its library releases (`dispose`/`close`/`cancel`) and which is never handed on except as a named argument. Ruby is read for the owned-and-never-released arm and the abandoned-local arm: a class declaring an instance `close`, `dispose`, `shutdown`, `stop`, `disconnect` or `terminate` whose instance variable is written only with a blockless core descriptor creation (`File.open`/`new`, `Tempfile`, `Dir.open`, `IO.popen`, the `socket` and `openssl` socket classes) that no method of the class closes and that is never handed on (passed, returned, stored, exposed by `attr_reader`, delegated) — a class whose superclass or mixin lies outside the repository is not judged — and a blockless creation read through and dropped (`File.open(path).read`) or held in a local that is never closed, returned, passed or stored (a `&:read` block-pass, an `autoclose: false` borrow and a `fileno` hand-over are not abandonment). PHP is read for the same two arms: a class (not a trait, and not one using a trait) declaring an instance `close`, `dispose`, `shutdown`, `stop`, `disconnect` or `terminate` whose `private` property (or a `final` class's `protected` one) is written only with a direct core `fopen`, `tmpfile`, `popen`, `proc_open`, `fsockopen`, `stream_socket_client`/`server` or `opendir` that nothing in the class closes (`fclose`, `pclose`, `closedir`, `unset`, a reset to `null`) and that is never handed on, and a handle held in a function's local, or read through as the argument of a reader, that is never closed, returned, passed, captured or stored; a `php://` stream, `curl_init`, `SplFileObject`, `PDO` and a function the repository declares under the core name are not read. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a method that temporarily changes state belonging to the whole process — the working directory, an environment variable — puts it back on EVERY path: a restore reached only when nothing throws leaks the change to the rest of the process.

Method: Roslyn syntax + semantics: method bodies that write the process working directory or an environment variable and write it back in the same body, checked for whether that restore sits in a `finally`/`catch` or only on the straight-line path. On a repository with no .NET source the same rule reads production JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not): `process.chdir`, `process.env.NAME =`/`["NAME"] =` and `delete process.env.NAME`, and Deno’s `Deno.chdir`/`Deno.env.set`/`Deno.env.delete`, paired per function body (a nested function or arrow is its own body, and module top-level code is none), where the last write puts back a local the body captured from the same global or deletes a variable the first write set, with at least one statement between them; a write in a `catch`/`finally` of that body silences it. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a `when` guard is free of side effects — a guard that increments a counter or assigns while deciding whether its arm matches applies that change during PATTERN MATCHING, on an arm that may not be selected, and skips it entirely when a short-circuit to its left answers first.

Method: Roslyn syntax: `when` guards on case labels and switch-expression arms, read for a mutation (`++`/`--`/assignment) sitting in a position the guard's own `&&`/`||`/`??`/`?:`/`?.` can skip. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a method that TAKES a lock or semaphore and gives it back from a flag-guarded `finally` returns the value that flag implies — reporting success while the guard hands the primitive back admits a second caller the exclusion was there to keep out, and reporting failure while the guard keeps it leaves nothing to ever give it back.

Method: Roslyn syntax: `try` statements whose `finally` releases a synchronisation primitive under a bare local-bool guard, where the method also TOOK that same primitive before the `try`, checked for a `return` of a bool literal whose value disagrees with the flag state the method's own straight-line assignments put it in. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether the work a diagnostic log line costs is paid only when that line is wanted — C# evaluates a call's arguments BEFORE the call, so a trace/debug message joined or projected out of a collection is built in full on every pass, and then discarded by a sink the shipped configuration leaves switched off.

Method: Roslyn syntax: log calls at a diagnostic level (a `Log`-prefixed method naming Trace/Debug/Verbose, or a bare `Debug`/`Trace`/`Verbose` on a receiver named for a logger), whose argument list is read for a call whose cost scales with a sequence — a LINQ operator, a materialisation, `string.Join`, a serializer — with no enclosing level check or conditional-compilation region. On a repository with no .NET source it reads JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not) with the same rule: a `debug`/`trace`/`verbose` call on a receiver named for a logger, or a `log`-prefixed method naming the level, whose argument calls an array operator (`map`/`filter`/`reduce`/`sort`/…), `Array.from`, `Object.keys/values/entries`, `JSON.stringify`/`util.inspect` over anything but a literal, or an array `join` — outside any arrow or function passed as an argument, which the logger calls only when the level is on — with no enclosing `if`, `&&` or `?:` whose condition names a level, a level string, or the `NODE_ENV`/`__DEV__`/`DEV` build switch. Deterministic, provable per finding. Advisory.

Other · Security — Whether text read out of the document being converted is escaped before it is written into generated markup — a value the document's author chose, interpolated into an attribute the surrounding literal delimits, can close that attribute and open another.

Method: Roslyn semantic model over the whole compilation: a string-typed `Value`/`InnerText`/`InnerXml`/`Text` member declared inside `DocumentFormat.OpenXml` or `System.Xml` is a taint SOURCE, propagated through assignments, returns, arguments, tuple elements and string composition to its transitive closure, then read at interpolated-string holes that sit in a markup position the surrounding literal itself delimits. Escaper/encoder calls and enclosing validator conditions cut the flow. Flow- and container-insensitive by construction. A second arm needs no provenance at all and reports a type that CONTRADICTS ITSELF — the same expression escaped at one delimited markup hole and interpolated raw at another hole in the same markup position of the same type, which the type's own escaping proves is a defect without knowing where the value came from. On a repository with no .NET source it reads JavaScript/TypeScript off the token stream with the same rule: a DOM read of raw document text (`getAttribute`, `textContent`, `innerText`, `nodeValue`) is the source, propagated through local bindings and string composition, and judged at template-literal and concatenation holes in the same two delimited markup positions; escapers and validating conditions cut it, and documentation-site, test, vendored and minified scripts are not read. Deterministic, provable per finding. Advisory.

• `document.getElementById('fa-eye').innerHTML` is text this program did not author, and it is written into the text of an element through `innerHTML` with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. Encode it for HTML at this site, render it through the framework's escaping output, or sanitise it if it must stay markup. (×2) — crates/mdbook-html/front-end/js/book.js:227, crates/mdbook-html/front-end/js/book.js:241
• `document.getElementById('fa-eye-slash').innerHTML` is text this program did not author, and it is written into the text of an element through `innerHTML` with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. Encode it for HTML at this site, render it through the framework's escaping output, or sanitise it if it must stay markup. — crates/mdbook-html/front-end/js/book.js:235
• `document.getElementById('fa-play').innerHTML` is text this program did not author, and it is written into the text of an element through `innerHTML` with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. Encode it for HTML at this site, render it through the framework's escaping output, or sanitise it if it must stay markup. — crates/mdbook-html/front-end/js/book.js:287
• `document.getElementById('fa-clock-rotate-left').innerHTML` is text this program did not author, and it is written into the text of an element through `innerHTML` with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. Encode it for HTML at this site, render it through the framework's escaping output, or sanitise it if it must stay markup. — crates/mdbook-html/front-end/js/book.js:311
• `url[0]` is text this program did not author, and it is written into a URL attribute through markup this function returns with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. Encode it for HTML at this site, render it through the framework's escaping output, or sanitise it if it must stay markup. — crates/mdbook-html/front-end/searcher/searcher.js:156
• `url[1]` is text this program did not author, and it is written into a URL attribute through markup this function returns with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. Encode it for HTML at this site, render it through the framework's escaping output, or sanitise it if it must stay markup. — crates/mdbook-html/front-end/searcher/searcher.js:157
• `result.doc.breadcrumbs` is text this program did not author, and it is written into the text of an element through markup this function returns with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. Encode it for HTML at this site, render it through the framework's escaping output, or sanitise it if it must stay markup. — crates/mdbook-html/front-end/searcher/searcher.js:158
• `content` is text this program did not author, and it is written into the text of an element through Handlebars' raw `{{{ }}}` output with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. Encode it for HTML at this site, render it through the framework's escaping output, or sanitise it if it must stay markup. — REDACTED:219
• `live_reload_endpoint` is text this program did not author, and it is written into a script or style context through Handlebars' raw `{{{ }}}` output with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. A script or style context needs its own escaping (or a JSON serialiser that escapes `<`); better, pass the value through a data attribute. — REDACTED:283
• `fragment_map` is text this program did not author, and it is written into a script or style context through Handlebars' raw `{{{ }}}` output with nothing encoding it for that place. Whoever controls the value controls the markup: it can close the element or attribute it sits in and open a script of its own. A script or style context needs its own escaping (or a JSON serialiser that escapes `<`); better, pass the value through a data attribute. (×2) — REDACTED:355, REDACTED:16

What to do

• Each finding names the expression, the attribute it lands in and the line. Confirm the value's origin from the read this analyzer traced, then escape it at the sink or validate it against the shape the attribute accepts before interpolating.

Other · Code Health — Whether a value the caller is invited to supply is the value the type actually uses — a constructor parameter stored in a private field that nothing ever reads while the default it was given is spelled out a second time at the site that should have read it, a keyed lookup that falls back to a different setting than the one its key names while the same type falls back to the matching one for that same key, or a culture-sensitive parse given no format provider by a type that feeds its own settable culture to the same kind of parse elsewhere, or a number an entry point writes to standard output under the host's culture while the same entry point formats with the invariant culture elsewhere. Either way, every caller who supplies a value silently gets something else.

Method: Roslyn syntax: private instance fields of a non-partial type assigned in a constructor from one of its own parameters with a `??` fallback, checked for whether anything in the type body reads the field and whether that same fallback expression is spelled out again outside the constructor; and `??` fallbacks onto a member access from a lookup call carrying exactly one string literal, grouped by that key across the type and checked for a fallback member whose folded name disagrees with the key while a sibling site for the same key agrees with it. On a repository with no .NET source the first two arms read JavaScript/TypeScript off the engine’s own token stream (tests included, bundles and vendored paths not): a `#x`, `private` or `private` parameter-property instance field filled in the constructor from a parameter (or one member of one) through `??`/`||` or a parameter default, never read anywhere in the file by name, whose constructed default is spelled again in the class body; and `lookup("key") ?? s.member` grouped by key per class, or per module outside every class. The culture arm has no JavaScript counterpart: its parses take no locale. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a `for` loop leaves the `RefCell` it is walking alone — safe Rust rejects a body that changes the collection its loop borrows at compile time, except through interior mutability: a `RefCell` borrowed in the loop's header stays borrowed until the loop ends, so a `borrow_mut()` of it inside the body panics with `already borrowed: BorrowMutError` and the remaining elements are never seen.

Method: Roslyn syntax + semantics: `foreach` statements whose body calls a structural mutator (`Add`/`Remove`/`Clear`/`Insert`/…) on the very expression the loop is enumerating. Two arms. ARM A — the source is a concrete fragile BCL collection, or a live `Keys`/`Values` view over one, and the mutator resolves to that same collection's own member; concurrent and immutable collections and arrays are outside the population by construction, since their enumerators survive a structural change. ARM B — the source is an argument-less accessor CALL on a receiver whose body is in source: the accessor must return a stored field VERBATIM and a sibling member must structurally change that same field, both read off the implementations rather than from the members' names. A mutation the loop provably exits immediately after (`break`/`return`/`throw`/`goto`), or one written inside a nested loop or a lambda, is counted and never reported. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a condition that tests a value for emptiness indexes that same value only where the test holds — an `||` written one parenthesis too far to the left leaves an index access outside the guard beside it, so the empty case the guard exists to anticipate reaches the index and throws.

Method: Roslyn syntax only, no semantic model: the OUTERMOST `&&`/`||` of every boolean condition, read for a symbol the condition tests for emptiness (`string.IsNullOrEmpty`/`IsNullOrWhiteSpace`, a `Length`/`Count` comparison against a literal, `Any()`, a `Length`/`Count` pattern, or a comparison against `""`) and ALSO indexes. Each `symbol[...]` access is placed by a boolean-reachability walk from the access up to the outermost connective: an access is COVERED when some enclosing step has it in the right operand and the left operand, under the truth value that step forces, proves the symbol non-empty — a recursion over `&&`/`||` whose true- and false-directions are asymmetric. A finding needs BOTH an uncovered access and a covered one on the same symbol in the same condition, which is the agreeing twin that separates a misplaced parenthesis from an unrelated length test. Bare index accesses with no emptiness test in the condition are neither counted nor reported; a non-identifier receiver and a lambda nested inside the condition are outside the population. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether a decision taken once per element is taken ABOUT that element — a test inside a counted loop that reads a fixed subscript of the very collection its guarded statement indexes by the loop variable applies element zero's answer to all of them, so the elements that differ from it are all handled wrongly, and in the same direction.

Method: Roslyn syntax only, no semantic model: every `for` statement declaring exactly ONE loop variable, and every `if` inside its body that is not under a nested loop or a lambda. A site enters the population when the `if`’s condition never mentions the loop variable while the statement it guards indexes some collection by that variable ALONE (`c[i]`; `c[i + 1]` and `c[i, j]` are outside it). A finding additionally needs the AGREEING TWIN at the same-collection grain: the condition must read THAT SAME collection at a subscript that does not move — written into the condition, or reached through a local declared BEFORE the loop, so an alias bound inside the body is not followed. Both collection expressions must be simple identifiers. On a repository with no .NET source the same rule reads JavaScript/TypeScript off the engine’s own token stream (tests included, bundles and vendored paths not): a `for (let|var|const x = …; …; …)` with one declarator and a braced body, an alias followed only when it is declared before the loop in a block that encloses it and never assigned inside the loop. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether exceptions are handled rather than silently swallowed or rethrown with lost stack traces.

Method: Roslyn syntax scan: every catch clause counted; empty catches and bare rethrows flagged. Population is all catch clauses, not estimated. Deterministic, hard fact.

• An empty catch block silently discards the error — failures vanish with no log and no rethrow. Log it, handle it, or don't catch it. (×4) — crates/mdbook-html/front-end/js/book.js:368, crates/mdbook-html/front-end/js/book.js:429, crates/mdbook-html/front-end/js/book.js:577, …

What to do

• Swallowed exception (empty catch)

Other · Code Health — Whether a guard written as a NEGATED `||` says what its author meant — `!(a || b || x != k)` is `!a && !b && x == k` by De Morgan, so a bail-out that mixes capabilities the code needs with a fault it refuses turns inside out: it fires only where the capabilities are ABSENT, and lets every value the fault term names walk straight into the body that cannot handle it.

Method: Roslyn syntax only, no semantic model: every logical-not whose operand is a parenthesised `||` chain of two or more disjuncts, flattened (a left-nested `a || b || c` read once would see `(a || b)` as one disjunct). A site enters the population on that shape alone. A finding additionally needs the disjuncts to DISAGREE in polarity: at least one bare boolean read — an identifier or member access, never an invocation, which is a predicate rather than a capability flag — and at least one `x != <constant>`, the only form that negates into an exact-value pin (`== null` negates into a looser requirement and is outside the fault set). Consistently-polarised disjunctions, all-fault or all-capability, are counted and never reported; a negated `&&` is outside the population entirely. No same-receiver gate: it was measured to cost a real defect and remove no false positive. Deterministic, provable per finding. Advisory.

Other · Code Health — Whether log calls use message templates (queryable) rather than interpolated strings.

Method: Roslyn syntax scan: every log call-site counted; interpolated-string first-argument violations flagged. Population is all log calls, not estimated. On a repository with no .NET source it reads JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not) with the same rule: a `trace`/`debug`/`info`/`warn`/`error`/`fatal`/`verbose`/`silly`/`http`/`log` call on a receiver named for a logger, in a package whose own or an enclosing `package.json` declares a logger that carries values as fields (pino, pino-http, nestjs-pino, Fastify, winston, bunyan, tslog, LogTape, roarr), whose first deciding argument is a template literal with substitutions; an object-literal fields argument is stepped over, a plain string message clears the call. Python is read the same way: a `debug`/`info`/`warning`/`error`/`exception`/`critical`/`log` call on a logger in a file that imports the standard library’s `logging` or structlog (loguru, which formats at the call, is not judged), whose message is a whole f-string with a non-constant field; a `%`-formatted, `.format()`-ed or concatenated message is not convicted, as in C#. PHP is read the same way: a PSR-3 level call (`emergency`…`debug`, `log`) on a logger (`$logger`, `$this->logger`, Laravel’s `Log::`, `logger()`, `\Drupal::logger()`) in a package whose `composer.json` requires a PSR-3 logger or a framework that hands one out (psr/log, Monolog, Laravel, Symfony, Drupal, CakePHP), or a file that imports one, whose message is a double-quoted string interpolating a variable; a single-quoted message clears the call, and `sprintf` or `.` concatenation is not convicted, as in C#. Dart is read the same way: a `trace`/`debug`/`info`/`warn`/`error`/`fatal` call on Sentry’s structured logger (`Sentry.logger`) whose message is a whole string literal interpolating a value (`$name`, `${…}`); the `Sentry.logger.fmt` template API clears the call. Dart that logs only through loggers with one message and no fields (package:logging, package:logger, talker, dart:developer) is not applicable rather than a reach gap. Ruby is read the same way: a `trace`/`debug`/`info`/`warn`/`error`/`fatal` call on the console gem’s `Console` (declared by a Gemfile, gemspec or Gemfile.lock, or required) or, where SemanticLogger, Ougai or dry-logger is declared or required, on a receiver named for a logger (`logger`, `@logger`, `Rails.logger`, `log`), whose first deciding argument is, as the whole argument, a double-quoted string interpolating a non-constant value (`#{…}`, `#@ivar`); a plain literal clears the call, keyword arguments are the fields, and a block, `%`-format or `+` concatenation is not convicted. Ruby that logs only through the standard Logger (Rails.logger) is not applicable rather than a reach gap. Deterministic.

• `error!` at line 142 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/main.rs:142
• `debug!` at line 76 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/init.rs:76
• `info!` at line 125 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `info!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/serve.rs:125
• `error!` at line 167 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/serve.rs:167
• `error!` at line 19 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:19
• `error!` at line 29 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:29
• `error!` at line 37 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:37
• `error!` at line 49 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:49
• `error!` at line 54 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:54
• `warn!` at line 75 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `warn!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:75
• `info!` at line 90 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `info!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:90
• `error!` at line 95 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:95
• `error!` at line 101 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:101
• `warn!` at line 116 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `warn!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/native.rs:116
• `error!` at line 24 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:24
• `trace!` at line 52 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `trace!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:52
• `info!` at line 59 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `info!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:59
• `error!` at line 64 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:64
• `error!` at line 71 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:71
• `warn!` at line 101 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `warn!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:101
• `trace!` at line 176 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `trace!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:176
• `debug!` at line 186 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:186
• `debug!` at line 200 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — src/cmd/watch/poller.rs:200
• `trace!` at line 202 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `trace!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:202
• `debug!` at line 208 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:208
• `debug!` at line 296 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:296
• `trace!` at line 445 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `trace!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:445
• `trace!` at line 477 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `trace!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:477
• `trace!` at line 489 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `trace!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:489
• `debug!` at line 495 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:495
• `trace!` at line 542 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `trace!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:542
• `warn!` at line 557 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `warn!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-summary/src/lib.rs:557
• `warn!` at line 111 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `warn!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-html/src/theme/mod.rs:111
• `info!` at line 135 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `info!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-html/src/theme/mod.rs:135
• `debug!` at line 138 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-html/src/html_handlebars/hbs_renderer.rs:138
• `debug!` at line 274 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-html/src/html_handlebars/hbs_renderer.rs:274
• `info!` at line 469 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `info!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-html/src/html_handlebars/hbs_renderer.rs:469
• `error!` at line 679 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `error!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-html/src/html_handlebars/hbs_renderer.rs:679
• `warn!` at line 58 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `warn!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-html/src/html_handlebars/search.rs:58
• `debug!` at line 253 is handed a format string with `{…}` values in it, so tracing records one finished `message` field — the values in it cannot be queried, filtered or aggregated as fields, and every occurrence reads as a different message. Record the values as fields beside a constant message instead: `debug!(order_id = %order_id, status = ?status, "order status updated")` (`%` records a value by its `Display`, `?` by its `Debug`, a bare name as itself), which a JSON subscriber, OpenTelemetry or a log store keeps as queryable keys. An error goes in as a field too: `error = %err`. — crates/mdbook-html/src/html_handlebars/static_files.rs:253

What to do

• Interpolated log message defeats structured logging