problem in finding "section" when adding arabic as second language

[proyan]

Hi Ricardo,

First of all, thanks for this excellent template. I used this for my thesis, and now I'm advising everyone around me to do the same.

I've run into an error when adding the language arabic to the tex file, in order to be able to add some quotes in arabic. Here is the basic example of the code that reproduces the error:

% **************************************************                                                                                                                                          
% Document Class Definition                                                                                                                                                                   
% **************************************************                                                                                                                                          
\documentclass[%                                                                                                                                                                              
    paper=A4,               % paper size --> A4 is default in Germany                                                                                                                         
    twoside=true,           % onesite or twoside printing                                                                                                                                     
    openright,              % doublepage cleaning ends up right side                                                                                                                          
    parskip=half,           % spacing value / method for paragraphs                                                                                                                           
    chapterprefix=true,     % prefix for chapter marks                                                                                                                                        
    11pt,                   % font size                                                                                                                                                       
    headings=normal,        % size of headings                                                                                                                                                
    bibliography=totoc,     % include bib in toc                                                                                                                                              
    listof=totoc,           % include listof entries in toc                                                                                                                                   
    titlepage=on,           % own page for each title page                                                                                                                                    
    captions=tableabove,    % display table captions above the float env                                                                                                                      
    chapterprefix=false,    % do not display a prefix for chapters                                                                                                                            
    appendixprefix=false,    % but display a prefix for appendix chapter                                                                                                                      
    draft=false,                                                                                                                                                                              
    configurebiblatex=false,                                                                                                                                                                  
    bibstyle=numeric,         % value for draft version                                                                                                                                       
]{scrreprt}%                                                                                                                                                                                  
                                                                                                                                                                                              
                                                                                                                                                                                              
% **************************************************                                                                                                                                          
% Setup YOUR thesis document in this file !                                                                                                                                                   
% **************************************************                                                                                                                                          
\input{my-thesis-setup}                                                                                                                                                                       
                                                                                                                                                                                              
                                                                                                                                                                                              
\usepackage{polyglossia}                                                                                                                                                                      
\setdefaultlanguage{english}                                                                                                                                                                 \
\setotherlanguage{arabic}                                                                                                                                                                     
                                                                                                                                                                                              
\begin{document}                                                                                                                                                                              
\section{Test Sentence}                                                                                                                                                                       
\end{document}

As you see, the document contains only one call to section.

As it is now, the code produces the following error:

(/usr/share/texmf/tex/latex/lm/t1lmss.fd)
(/usr/share/texmf/tex/latex/tex-gyre/t1qhv.fd)
! Undefined control sequence.
\in@ #1#2->\begingroup \def \in@@ 
                                  ##1#1{}\toks@ \expandafter {\in@@ #2{}{}#1...
l.34 \section{Test Sentence}
                            
? 
! Illegal parameter number in definition of \@themark.
<to be read again> 
                   1
l.34 \section{Test Sentence}
                            
? 
! Undefined control sequence.
\in@ ...f \in@@ ##1#1{}\toks@ \expandafter {\in@@ 
                                                  #2{}{}#1}\edef \in@@ {\the...
l.34 \section{Test Sentence}
                            
? 
! Undefined control sequence.
\in@ ... \expandafter {\in@@ #2{}{}#1}\edef \in@@ 
                                                  {\the \toks@ }\expandafter...
l.34 \section{Test Sentence}
                            
? 
! Extra \else.
\H@old@sect ... }{\scr@ds@tocentry }\fi \fi \else 
                                                  \def \@svsechd {#6{\sectio...
l.34 \section{Test Sentence}

However, if I remove the line \setotherlanguage{arabic}, everything works. Also, If I don't use the sty package cleanthesis, everything works. So it looks like cleanthesis is doing something to section that doesn't work with the arabic language. Though I can't seem to figure out what.

I wonder if you could please help me with it.

I'm using cleanthesis 2019/06/21 v0.4.0, and XeTeX, Version 3.14159265-2.6-0.99992 to compile

Thanks,
Rohan