xticklabels from table not working [duplicate]

The content

\documentclass[margin=1cm]{standalone}

\usepackage{filecontents}
\usepackage{pgfplots}

\begin{filecontents}{dummy.txt}
category,amountTotal
excellent,0
good,8
neutral,2
not good,0
poor,0
\end{filecontents}

\begin{document}
\begin{tikzpicture}
\begin{axis}
[
ybar,
symbolic x coords={excellent,good,neutral,not good,poor},
xtick=data,
x tick label style={rotate=45,anchor=east},
%xticklabels from table={dummy.txt}{category}
]
%\addplot coordinates {(excellent,0) (good,8) (neutral,2) (not good,0) (poor,0)};
\end{axis}
\end{tikzpicture}
\end{document}


compiles just fine with lualatex -shell-escape filename.tex. However, when I try to get the xticklabels from the file dummy.txt by means of the command xticklabels from table={dummy.txt}{category}

\documentclass[margin=1cm]{standalone}

\usepackage{filecontents}
\usepackage{pgfplots}

\begin{filecontents}{dummy.txt}
category,amountTotal
excellent,0
good,8
neutral,2
not good,0
poor,0
\end{filecontents}

\begin{document}
\begin{tikzpicture}
\begin{axis}
[
ybar,
%symbolic x coords={excellent,good,neutral,not good,poor},
xtick=data,
x tick label style={rotate=45,anchor=east},
xticklabels from table={dummy.txt}{category}
]
%\addplot coordinates {(excellent,0) (good,8) (neutral,2) (not good,0) (poor,0)};
\end{axis}
\end{tikzpicture}
\end{document}


I get the error

! Package pgfplots Error: Table 'dummy.txt' appears to have too many columns in
line 8: Ignoring 'good,0'. PGFPlots found that the number of columns is larger
than the previously determined number of columns. Please verify that every cel
l entry is separated correctly (use braces {<cell entry>} if necessary. Also ve
rify that column names are plain ASCII.). This error is not critical.


What am I doing wrong? Does xticklabels from table understand that the column separator is in this case a comma?