Biblatex and apa style: reviewauthor undefined warning

Question

I get the warning,

Package biblatex warning: Macro 'reviewauthor' undefined

when running the following,

\documentclass{article}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
    @Book{elvis,
    author = "Elvis Presley",
    title = "Turn Me One More Time",
    publisher = "Jail House Books",
    year = 1963,
}
\end{filecontents}
\usepackage[american]{babel}
\usepackage{csquotes}
\usepackage[style=apa,backend=biber]{biblatex}
\DeclareLanguageMapping{american}{american-apa}
\addbibresource{\jobname.bib}

\begin{document}
Here is a citation \textcite{elvis}

\printbibliography
\end{document}

When using, say style=authoryear there's no warning.

Now this doesn't seem to cause any untoward effects yet but I hate warnings since they have a habit of coming back and haunting you later.

Any ideas what this is about?

Answer 1

The warning is harmless. The reasons why it is generated is because the apa style declares \renewbibmacro{reviewauthor} and the macro reviewauthor is not defined in the files loaded by the style.

However, the BibLaTeX manual, for \renewbibmacro, specifies

Similar to \newbibmacro but redefines ⟨name⟩. In contrast to \renewcommand, \renewbibmacro issues a warning message if the macro is undefined, and automatically falls back to \newbibmacro.