How to use pstricks with XeLaTeX and tufte-book class? [duplicate]

Question

I would like to use the beautiful tufte-book class together with some pictures created using pstricks. XeLaTeX is needed to work with pstricks, however when I run this with the tufte-book class I get the error "Argument of \MakeTextLowerCase has an extra }". It seems that the error is caused by the \title command. Below is some minimal code that gives an error (if I remove the \title command then it runs correctly).

Is there any way I can use pstricks and tufte-book class with a title?

\documentclass{tufte-book}

\usepackage{pstricks}

\title{Test title}

\begin{document}

\begin{pspicture*}(-1,-1)(2,1)
\psline[linewidth=1pt](0,0)(1,0)
\end{pspicture*}

\end{document}

Answer 1

With this tufte-common.def I can run it with xelatex and also with lualatex (should be preferred)

Answer 2

This is basically a duplicate of Letterspacing, Minion Pro, and Tufte-LaTeX (problem with running header)

I add a CW answer in order to show the details here.

Note that pstricks has nothing to do with the issue, which is caused by soul.

You need to redefine the “(small) caps spacing” commands, but in order for this to work you must declare the fonts used with the fontspec methods.

\documentclass{tufte-book}
\usepackage{microtype}
\usepackage{pstricks}

\setmainfont{Latin Modern Roman}[
  SmallCapsFont={Latin Modern Roman Caps}
]

\renewcommand\allcapsspacing[1]{{\addfontfeature{LetterSpace=15}#1}}
\renewcommand\smallcapsspacing[1]{{\addfontfeature{LetterSpace=10}#1}}

\title{Test title}

\begin{document}

\begin{pspicture*}(-1,-1)(2,1)
\psline[linewidth=1pt](0,0)(1,0)
\end{pspicture*}

\end{document}