[sergo] Sergo Report: New 19th-Linter Enforce Audit (fmterrorfnoverbs) - 2026-06-01

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🔬 Sergo Report: reverify-plus-new-fmterrorfnoverbs-19th-linter-enforce-audit

Date: 2026-06-01 · Run: R25 · Success Score: 9/10

Executive Summary

This run reverified last run's enforce candidate and discovered a brand-new linter. sg24a1 (uncheckedtypeassertion) fully landed: the maintainer appended -uncheckedtypeassertion to cgo.yml:1040 (now 10 enforced flags), and the two regressed pass.ResultOf[...] type-assertions were refactored to the safe two-value form. The audit → fix-to-zero → enforce pattern has now held 4 consecutive runs (R22→R25).

The registry grew 18 → 19 linters: the new fmterrorfnoverbs flags fmt.Errorf("literal") with no % verbs (where errors.New is idiomatic and cheaper). It is registered but unenforced. The headline finding is a build-constraint subtlety: a naive grep reports 16 violations, but only 2 are enforceable under CI's default linux build — the other 14 live in *_wasm.go files excluded by the implicit GOARCH=wasm filename constraint. Critically, this linter has no //nolint escape hatch, so fix-to-zero is the only enforcement path. One issue was filed.

🛠️ Serena Tools Update

• Total Serena tools: 23 (stable R4→R25, 22 consecutive runs — no change)
• New / Removed / Modified: None
• Tools used today: activate_project (project load), plus Grep/Read for the LSP-adjacent symbol/pattern work (Serena find_symbol remains slower than Grep for broad sweeps).
• Linter registry (the real "tool" surface here): 18 → 19 — fmterrorfnoverbs added at cmd/linters/main.go:25,49.

📊 Strategy Selection (50% cached / 50% new)

Cached Reuse (50%) — reverify the prior enforce candidate

• Adapted from: R24 reverify-plus-uncheckedtypeassertion-... (score 9).
• Why: the reverify-then-enforce loop is the highest-ROI proven move (landed R22, R23, R24).
• Result: sg24a1 RESOLVED & ENFORCED — -uncheckedtypeassertion is flag Remove ai-inference, opencode, genaiscript agentic engines for now #10 at cgo.yml:1040; jsonmarshalignoredeerror.go:26 and strconvparseignorederror.go:34 now use insp, ok := ...; if !ok { return nil, fmt.Errorf(...) }.

New Exploration (50%) — scan for a newly-registered linter

• Hypothesis (from R24 stats): registry grows ~1 linter every few runs; watch for a 19th.
• Confirmed: fmterrorfnoverbs is the new 19th linter. Audited it end-to-end: violation count, build-constraint visibility, //nolint support, and the precise fix per file.

Combined Rationale

Reuse confirms the pipeline keeps delivering; exploration refills it. Together they sustain the enforce-landing flywheel without re-filing dismissed issues.

🔍 Analysis Execution

• Go files: ~1,200+ (pkg/ focus) · Linters registered: 19 (10 enforced, 9 unenforced)
• Focus: pkg/linters/fmterrorfnoverbs, cmd/linters/main.go, .github/workflows/cgo.yml:1040, and all fmt.Errorf no-verb call sites.

Findings Summary

• Total issues: 6 (1 resolved-on-reverify, 1 new actionable, 4 informational) · Critical 0 · High 0 · Medium 1 · Low/Info 5

📋 Detailed Findings

Medium — fmterrorfnoverbs registered but unenforced (sg25a1, issue filed)

New 19th linter, no //nolint support. 16 grep hits; only 2 enforceable under host build:

• Enforceable now: pkg/workflow/utc_offset.go:18 and :24 (no build tag; fmt retained via Sprintf).
• Wasm-only (excluded from host lint): 14 sites across 7 *_wasm.go files (console/*, parser/github_wasm.go, workflow/git_helpers_wasm.go, workflow/github_cli_wasm.go).

Informational findings

• sg24a1 RESOLVED+ENFORCED (reverify): uncheckedtypeassertion is flag Remove ai-inference, opencode, genaiscript agentic engines for now #10; both newest analyzers refactored to two-value ResultOf.
• Build-constraint partitioning rule: *_wasm.go filenames imply GOARCH=wasm — always partition grep hits by build tag before claiming "N enforceable." Recorded to memory.
• Linter minor bug: fmterrorfnoverbs checks len(Args)==0 then Args[0] but not len(Args)==1; fmt.Errorf("msg", extra) (no verb, extra arg) would be flagged and an errors.New fix would silently drop extra. Rare and already-buggy input; noted as observation only.
• Parity gap: this linter lacks nolint.BuildLineIndex that siblings have — possible R26+ follow-up.
• No backtick/raw-string no-verb Errorf variants exist.

✅ Improvement Task Generated

Task — Enforce fmterrorfnoverbs (Medium, Small effort): convert utc_offset.go (2 sites) to errors.New; optionally convert the 14 wasm-stub sites for parity (swap "fmt" → "errors" import per file); then append -fmterrorfnoverbs to cgo.yml:1040. Validate with make golint-custom (host) and GOOS=js GOARCH=wasm go build ./....

📈 Success Metrics

• Findings: 6 · Tasks/Issues: 1 · Score: 9/10 — clean reverify confirmation + a fully-characterized new enforce candidate with a non-obvious build-constraint insight. Not 10: only one net-new actionable item.

📊 Historical Context

• Total runs: 25 · Total findings: 204 · Total tasks: 51 · Avg score: 8.67
• Enforce-landing streak: 4 consecutive (R22→R25). Enforced flags: 9 → 10.

🎯 Recommendations

1. Immediate: adopt sg25a1 — fix utc_offset.go (2 lines) and enforce -fmterrorfnoverbs. Lowest-effort, highest-certainty win.
2. Parity: fix the 14 wasm stubs so a future GOARCH=wasm lint stays clean.
3. Long-term: add //nolint (BuildLineIndex) support to fmterrorfnoverbs for consistency with siblings.

🔄 Next Run Preview

• R26: reverify sg25a1 landing. After it lands, clean enforce candidates are again exhausted unless a 20th linter appears — pivot to errormessage opt-in scoping or a scoped ctxbackground (28-site) refactor proposal.

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Generated by Sergo — The Serena Go Expert · Run ID: 26736678212 · Strategy: reverify-plus-new-fmterrorfnoverbs-19th-linter-enforce-audit

Generated by 🤖 Sergo - Serena Go Expert · opus48 1.7M · ◷

• expires on Jun 2, 2026, 5:28 AM UTC

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