How to get mathit font to match $x$ (using Computer Modern) when main font is different?

Question

I'm setting a book with main text font Source Serif Pro while sticking with Computer Modern math font. (Those may not be the best choices, but for the time being, I am stuck with them.) But \mathit is not behaving as I hope. I want $v$ and $\mathit{vs}$ to look compatible, but instead they look startlingly different.

Here's the code:

\documentclass{article}
\usepackage{fontspec}
\setmainfont{Source Serif Pro}[Scale=MatchLowercase]
\begin{document}
\thispagestyle{empty}
Singular $v$, plural $\mathit{vs}$, list \texttt{(cons $v$ $\mathit{vs}$)}.
\end{document}

I have found the question How do I change the math italic font in XeTeX/fontspec? and I have poked at the documentation for the mathspec and fontspec packages, and fontspec preserves the Computer Modern symbols just as I had hoped. How can I tell \mathit that I want it to do the same thing it did under Computer Modern?

Answer 1

use the no-math option

\documentclass{article}
\usepackage[no-math]{fontspec}
\setmainfont{Source Serif Pro}[Scale=MatchLowercase]
\begin{document}
\thispagestyle{empty}
Singular $v$, plural $\mathit{vs}$, list \texttt{(cons $v$ $\mathit{vs}$)}.
\end{document}