\usepgfplotslibrary{lib1,lib2} may give wrong output

[muzimuzhi]

From TeX-SX question https://tex.stackexchange.com/q/568789

Compared to loading one lib at a time, loading multiple libs at a time may give wrong output.

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.17}

% get expected result
\usepgfplotslibrary{statistics}
\usepgfplotslibrary{fillbetween}

% get wrong result, the circled marker is not drawn
%\usepgfplotslibrary{statistics,fillbetween}

\begin{document}
\begin{tikzpicture}
    \begin{axis}[boxplot/draw direction = y]
        \addplot [boxplot] table [col sep=comma,y index=0] {
          1
          1
          2
          1
          1
          3
          5
        };
    \end{axis}
\end{tikzpicture}
\end{document}

In the TeX-SX answer given by @u-fischer, she pointed out that the problem is caused by https://github.com/pgf-tikz/pgfplots/blob/e4b3ec4c9caeb7444487a1d0e87cadedbed6893d/tex/generic/pgfplots/libs/pgfplotslibrary.code.tex#L53-L57 in definition of \use@@pgfplotslibrary, and

The problem is that #1 is statistics,fillbetween or fillbetween,statistics if you combine both in one command, and so the test is always false.

So it is a bug but simply replacing #1 by \pgf@temp does not work, as these library calls can be nested and so the value is not correct in all cases.

[marmotghost]

IMHO the more important issue is that the wrong library gets loaded, see https://tex.stackexchange.com/a/568816/227820.