Re: Potential regression in natbib/beamer citation formatting in TeXLive 2026

Am 29.03.26 um 01:57 schrieb Steven Paulson:
>
> Dear TeXLive Team,
>
> I am writing to report a potential bug regarding citation formatting 
> that appears when using the TeX Live 2026 distribution (verified on 
> texlive.net/run <http://texlive.net/run>).
>
> *Description:* When using |natbib| with the |beamer| document class, 
> the citation punctuation (specifically the comma and parentheses 
> placement) is not being rendered correctly.
>
>  *
>
>     *Observed output:* |(Vaswani et al.2017)| and |Vaswani et al.2017|
>
>  *
>
>     *Expected output:* |(Vaswani et al., 2017)| and |Vaswani et al.
>     (2017)|
>
> It seems the |round| and |authoryear| options in |natbib| are being 
> ignored or overridden in this environment. Downgrading back to TeXLive 
> 2025 solves the issue.
>

Use biblatex with biber:

\begin{filecontents}[overwrite]{refs.bib}
     @article{vaswani2017attention,
         title={Attention is all you need},
         author={Vaswani, Ashish and Shazeer, Noam and Parmar, Niki and 
Uszkoreit, Jakob and Jones, Llion and Gomez, Aidan N and Kaiser, 
{\L}ukasz and Polosukhin, Illia},
         journal={Advances in neural information processing systems},
         volume={30},
         year={2017}
     }
\end{filecontents}

\documentclass{beamer}
\usepackage[style=authoryear,natbib]{biblatex}
\addbibresource{refs.bib}

\begin{document}

\begin{frame}{Introduction}
     \begin{itemize}
         \item Observed \citep{vaswani2017attention} (Missing comma)
         \item Observed \citet{vaswani2017attention} (Missing 
parentheses around year)
     \end{itemize}
\end{frame}

\begin{frame}[fragile]{References}
     \printbibliography
\end{frame}

\end{document}



Herbert