latex-repair

name	latex-repair
description	Use when a LaTeX build fails or produces a broken PDF in Stage 07 (Writing) — undefined control sequences, missing style packages, unresolved citations or references, float placement blowing the page budget, or a build_log.txt full of errors you need to triage.

LaTeX repair

Stage 07's gate wants workspace/writing/main.tex, section files, a bibliography, a compiled PDF, and workspace/artifacts/build_log.txt. When the build fails, the loop to avoid is: change something, recompile, read the same error, change something else. LaTeX reports the first thing that broke, and one real cause usually generates a cascade of downstream errors.

Triage order

Read build_log.txt from the top and fix in this order. Recompile after each class, not after each edit.

1. Missing style package — LaTeX Error: File 'neurips_2025.sty' not found. AutoR does not vendor official style files (templates/registry.yaml says so and carries the venue's official_url). Either fetch the style package to workspace/writing/, or fall back to a standard class and record the substitution honestly in the stage summary. Do not silently switch venue.
2. Undefined control sequence — a command from a package that is not loaded, or a typo. Check the preamble before assuming the command is wrong.
3. Missing $ / runaway argument — almost always an unescaped _, %, & or # in prose that came from a variable name or a file path. These are common when text was assembled from JSON results.
4. Undefined references and citations — LaTeX Warning: Citation 'x' undefined. Requires a bibtex/biber pass and then two more LaTeX passes. A single compile will always report these.
5. Overfull boxes and float drift — cosmetic until they push the paper past the venue page limit, at which point they are a submission blocker.

Compile sequence

A one-shot compile cannot resolve cross-references or citations. The minimum is:

pdflatex main.tex   # writes .aux
bibtex main         # or biber, per the venue's citation_style
pdflatex main.tex   # resolves citations
pdflatex main.tex   # resolves page-dependent references

If latexmk is available, latexmk -pdf main.tex does this correctly and is the better default. Whatever you run, tee the full output to workspace/artifacts/build_log.txt — the gate reads that file, and a log containing only the last pass hides the errors from the earlier ones.

When the toolchain is not installed

If no LaTeX toolchain exists in the environment, say so in the stage summary and in build_log.txt, and do not fabricate a PDF. A file named main.pdf that is not a PDF fails later and more confusingly than a missing one. Check whether the run should be using --output-format markdown instead — that path has no LaTeX dependency at all.

Errors that are really content problems

Log line	Actual cause
Citation 'foo2024' undefined after a full bibtex cycle	The key is not in the .bib. Use the citation-discipline skill; do not invent the entry.
Reference 'fig:main' undefined	The figure was cited before it was written, or the label is on the wrong element.
File 'figures/main.pdf' not found	Stage 06 wrote figures under workspace/figures/; the path in the .tex is relative to the main file, not to the workspace root.
Page count over the venue limit	Not a LaTeX bug. Check templates/registry.yaml for page_limit and refs_in_limit, then cut content rather than shrinking margins — most venues reject the second.

Before you finish

• The PDF opens and has the expected number of pages.
• No ?? or [?] markers survive in the rendered text.
• build_log.txt contains the whole build, including the passes that succeeded.
• If a style package was substituted, the stage summary says which and why.