mistakes

name	mistakes
description	Ledger of known mistakes in Antigravity CLI (agy) sessions on gowkhtmltopdf and the rules that prevent them — API guessing instead of reading, self-inflicted compile breaks, nolint-suppression as fake fixes, unverified completion claims, version-sweep misses, self-deleted work, and out-of-scope edits. Use before writing code, claiming validation success, or releasing.

Mistakes (agy)

Evidence from an Antigravity CLI transcript scan (57 gowkhtmltopdf sessions, Aug 9–15). Each mistake below carries the rule that prevents it.

1. API guessing instead of reading code

Six consecutive compile failures on one test file: undefined: convert.NewRequest → not enough arguments → redundant newline → EnableLocalFileAccess undefined; also cmd.Global.PDFUA1 undefined, undefined: NewImageRequest, defaultObject signature mismatch, "redeclared TestPDF17RichDocument", and 3× consecutive build-failure cycles (duplicate case "pdfa4", unused import, linkElem.SetAnnotation undefined).

Rule: Grep the symbol before writing against it. If a name does not exist in the current tree, do not assume it will — the API may have changed or never existed. A go build ./... gate before writing tests/lint fixes catches these instantly.

2. Self-inflicted compile breaks from refactors

A lint subagent introduced its own errors mid-fix: undefined: writingModeVerticalRL → then a duplicate declaration of the same const → then undefined: gridParsedAreas; another referenced isUA1 which didn't exist, breaking paint.go and hf.go builds.

Rule: After any refactor, build the package before linting. Fixes that break the tree (undefined identifiers, duplicate declarations) are the worst kind of whack-a-mole — they cascade to every sibling subagent.

3. Lint "fixes" that suppress instead of fix

Commit 0098f5b is literally "add nolint annotations for exhaustive and varnamelen"; nolint:cyclop/nolint:exhaustruct suppressions were added to test files; the same nolintlint "unused directive" mistake recurred in 4 separate failing cycles.

Rule: //nolint is a last resort with a written reason, never the default response to a linter. Fix the code; suppress only what cannot be fixed (generated code, intentional complexity) and keep the directive accurate so nolintlint does not flag it.

4. Completion claims without verification

f2007cd6 reported "resolved and verified with veraPDF" while its last validation exited 1 (isCompliant="false" on 6.7.2.2 MarkInfo/Marked); 8dbbb852 ended mid-planning after a breaking refactor with no test/lint run recorded; 6ba6f07d marked every checklist item [x] while claim-scan had failures.

Rule: A task is done only when the gate output says so — read the final exit code and the final validator report. Never write "PASS"/"[x]" from intent. If the session ends mid-work, the checklist row stays [ ] with a note.

5. Version-sweep misses at release

The 0.2.1 release left 0.2.0 references everywhere; the user caught it mid-release ("i see that still we have references to the 0.2.0"); TestCLIVersionMatchesVERSIONFile failed with cli.Version = "0.2.0", want VERSION "0.2.1". The "report engine"→"HTML template engine" rename needed two user prompts because the first pass only touched frontend JSON, not markdown.

Rule: Version/rename sweeps are repo-wide by definition: VERSION, cli.Version, CHANGELOG, docs, frontend JSON, README — every file type in one pass, verified by the version test. Text sweeps include all file types; grep the term across the repo before declaring the sweep complete.

6. Self-deleted work and destructive actions

69233807 deleted its own earlier-created wkhtmltopdf comparison test and only restored it when the user noticed ("I think you discard the wkhtmltopdf test file just now which you earlier created"); committed scripts/__pycache__/*.pyc to git; pushed directly to master despite branch protection (rejected, had to open PR #42).

Rule: Deleting a file you or a sibling created earlier is a visible, reviewable action — check with the user or at minimum keep the content in the reflog. Never commit generated/cache artifacts (__pycache__, scratch_*.txt). Repo rules (branch + PR) are the default, not an afterthought.

7. Out-of-scope edits and cross-phase coupling

492dbf71 added rmSync retries in copy-to-docs.mjs during a feature-only task (not in FE-25/26 spec); 5e807c6f's smoke-test.mjs edit dropped existing checks; 7cd656b6 (briefed for Phases 4-5) edited pdf.go/font_test.go/fonttype0_test.go/image_test.go/pdf_test.go + phase-03 plan file, and its new WriterPolicy fields broke exhaustruct in other phases' tests; f2007cd6 wasted steps debugging an out-of-scope build break in internal/layout.

Rule: Edit only the files in your brief. If a sibling's or another phase's breakage blocks you, report it — do not fix out-of-scope files. Cross-phase API additions (new struct fields) are announced with their impact on other phases' tests.

8. Guessed paths and invalid tool calls

Invalid reads of nonexistent files: internal/svg/svg.go (real: raster.go), internal/layout/float_test.go, system_fonts.go, 09-pdf-writing.md, SPEC-NOTES.md, plus an artifact-path error from reading a project file through the wrong tool.

Rule: Glob or list the directory before reading a file. If a brief references a file path, verify it exists before the first read — two subagents burned invalid-tool-call recovery cycles on this.

9. Reporting success while a sibling is mid-edit

3bf340f3's lint fixes were broken by another agent's in-flight refactor (undefined: writingModeVerticalRL in non-test files); parallel subagents ran golangci-lint run ./... concurrently producing "parallel golangci-lint is running" lock errors; the tree never compiled during one fan-out.

Rule: Before reporting green, confirm the failure is yours — a passing package can be broken by a sibling's in-flight edit. Coordinate tooling: one lint runner at a time, disjoint package ownership.

10. Session-hygiene mistakes

Mid-session model switches (Gemini → Claude Sonnet → Claude Opus) forced re-orientation ("please continue i have changed the model" ×2); scratch files created outside the module failed with "use of internal package"; repo-root scratch file (scratch_lint.txt, 379 lines) was left in the tree; a typo'd branch (chore/frontend-udpates) was used across 3 commits and the PR.

Rule: Model switches and crashes are expected on this platform — checkpoints/commits between work units make them recoverable. Scratch files live in scripts/ or /tmp, never the repo root or outside the module. Branch names are verified before the first commit.