rohitg00/ai-engineering-from-scratch · error · PaperValidationError

duplicate bibliography key: {b.key}

Error message

duplicate bibliography key: {b.key}

What it means

Error "duplicate bibliography key: {b.key}" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at phases/19-capstone-projects/54-paper-writer/code/main.py:91

ProseGenerator = Callable[[Section, Paper], str]


def _validate(paper: Paper) -> None:
    if not paper.title.strip():
        raise PaperValidationError("title is empty")
    if not paper.abstract.strip():
        raise PaperValidationError("abstract is empty")

    fig_ids: set[str] = set()
    for fig in paper.figures:
        if fig.id in fig_ids:
            raise PaperValidationError(f"duplicate figure id: {fig.id}")
        fig_ids.add(fig.id)

    bib_keys: set[str] = set()
    for b in paper.bibliography:
        if b.key in bib_keys:
            raise PaperValidationError(f"duplicate bibliography key: {b.key}")
        bib_keys.add(b.key)
    for sec in paper.sections:
        for key in sec.cites:
            if key not in bib_keys:
                raise PaperValidationError(
                    f"section {sec.id!r} cites unknown bibliography key {key!r}"
                )
        for fid in sec.figure_refs:
            if fid not in fig_ids:
                raise PaperValidationError(
                    f"section {sec.id!r} references unknown figure id {fid!r}"
                )


def _escape_latex(text: str) -> str:
    repl = {
        "\\": r"\textbackslash{}",
        "&": r"\&",

View on GitHub (pinned to 39ea8a1c6d)

When it happens

Trigger: Thrown at phases/19-capstone-projects/54-paper-writer/code/main.py:91 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rohitg00/ai-engineering-from-scratch@39ea8a1c6d (2026-08-26). Data as JSON: /api/errors/c6e07b306409f71c. Report an issue: GitHub.