# List of tcolorbox in tufte-book

Normally \tcblistof works fine, but not with the tufte-book class and I cannot figure out why. Here is a MWE.

\documentclass{tufte-book}
% \documentclass{book} % this works
\usepackage[theorems]{tcolorbox}
\newtcbtheorem[auto counter,number within=chapter,list inside=thm]{theo}{Theorem}{}{}

\begin{document}
\tcblistof[\chapter*]{thm}{List of Theorems}
\chapter{Chapter No1}
\begin{theo}{Theorem No1}{}
lipsum
\end{theo}
\end{document}


Using the book class works as expected. What do I have to change for tufte-book?

OP has already found a solution in this answer. Here I'd like to provide some general discussions.

tufte-book class contains lines

% Only show the chapter titles in the table of contents
\setcounter{tocdepth}{0}


and since tcolorbox defines \l@tcolorbox as level 1 by

\newcommand*\l@tcolorbox{\@dottedtocline{1}{1.5em}{2.3em}}


therefore \tcblistof[\chapter*]{thm}{List of Theorems} produces nothing but a list title.

Locally using \setcounter{tocdepth}{1} is a workaround, but the produced list entries may not share the same style with list of figures and tables. Currently entries in these two list are defined as

\newcommand{\@tufte@lof@line}[2]{%
% #1 is the figure/table number and its caption text
% #2 is the page number on which the figure/table appears
\leftskip 0.0em
\rightskip 0em
\parfillskip 0em plus 1fil
\parindent 0.0em
\@afterindenttrue
\interlinepenalty\@M
\leavevmode
\@tempdima 2.0em
\null\nobreak\hskip -\leftskip
\par%
}

\renewcommand*\l@figure{\@tufte@lof@line}
\let\l@table\l@figure


Hence OP's answer \let\l@tcolorbox\l@figure is a good idea.

It seems to work if I add

\makeatletter
\let\l@tcolorbox\l@figure
\makeatother