Problem with bidi in polyglossia

Question

Any help please for this message error?

! Package Listings Error: direction textdirection unknown.

I'm using polyglossia, and getting this error after updating to texlive 2018.

I managed to limit the error in tcolorbox package in preambule. Here is a simple code that results the error:

% !TeX TS-program = xelatex
\documentclass[12pt,a4paper]{article}

\usepackage{xcolor}
\colorlet{mygray}{gray!6!white}

\usepackage[most]{tcolorbox}

\newtcolorbox{myindex}{ %somthing wrong happens here
arc=2mm,
colback=white,
}

\usepackage{fontspec}
\setmainfont[Scale=1.15]{Amiri}

\usepackage{polyglossia}
\setmainlanguage[locale=morocco]{arabic}

\begin{document}
عربي
\end{document}

Answer 1

UPDATE

With version 33.2 of bidi, released 2018/09/15, the issue has been solved. Note that listings version 1.7, released 2018/09/02 (or later) has to be used or the issue would present itself again.

---

Original answer

The error is in the helper file listings-xetex-bidi.def where the starting code is

\lst@Key{captiondirection}{textdirection}{%
    \lstKV@SwitchCases{#1}%
    {textdirection&\\%
     RTL&\chardef\bidi@lst@caption@direction\@ne\\%
     LTR&\chardef\bidi@lst@caption@direction\z@%
    }{\PackageError{Listings}{direction #1 unknown}\@ehc}}

\lst@Key{captionscript}{textscript}{%
    \lstKV@SwitchCases{#1}%
    {textscript&\\%
     latin&\chardef\bidi@lst@caption@script\@ne\\%
     nonlatin&\chardef\bidi@lst@caption@script\z@%
    }{\PackageError{Listings}{direction #1 unknown}\@ehc}}

which is wrong. The \lstKV@SwitchCases macro wants a different delimiter than &; the correct code should be

\lst@Key{captiondirection}{textdirection}{%
    \lstKV@SwitchCases{#1}%
    {textdirection:\\%
     RTL:\chardef\bidi@lst@caption@direction\@ne\\%
     LTR:\chardef\bidi@lst@caption@direction\z@%
    }{\PackageError{Listings}{direction #1 unknown}\@ehc}}

\lst@Key{captionscript}{textscript}{%
    \lstKV@SwitchCases{#1}%
    {textscript:\\%
     latin:\chardef\bidi@lst@caption@script\@ne\\%
     nonlatin:\chardef\bidi@lst@caption@script\z@%
    }{\PackageError{Listings}{direction #1 unknown}\@ehc}}

Note that : should go instead of &.

To the bidi author's discharge, the change in syntax is quite recent (just a few days) and in the previous versions of listings the delimiter used to be &. See https://sourceforge.net/p/persian-tex-dist/tickets/9/

Indeed, a minimal example showing the error is

\documentclass[12pt,a4paper]{article}

\usepackage{listings}
\usepackage{fontspec}
\usepackage{polyglossia}

\setmainlanguage[locale=morocco]{arabic}
\setmainfont[Scale=1.15]{Amiri}

\begin{document}
عربي
\end{document}

It appears in your document because the most option to tcolorbox loads listings. If you don't need listings just avoid loading it and issue

\usepackage[many]{tcolorbox}

manually loading the possible missing libraries.

If you do need listings there's little to do except to copy listings-xetex-bidi.def into your working directory and change the six appearances of & into : as shown above, at least until the wrong code is fixed in the bidi distribution.