newtx conflicts with fontspec in TeX Live 2022

Question

After upgrading to TeX Live 2022, I found a lot of my previous code broken due to the clash between newtx and fontspec. Here is a minimal example (The engine is XeLaTeX under Windows):

\documentclass[11pt]{article}
\usepackage{xeCJK}
\usepackage{newtxtext} % !!!
\usepackage{newtxmath} % !!!
\usepackage{fontspec}

\setsansfont{TeX Gyre Heros}
\setCJKmainfont{Noto Serif CJK SC}

\begin{document}
    \[ x^2+y^2=z^2 \]

    Test English.

    测试中文。
\end{document}

The code will not compile and shows error:

! Package fontspec Error: The font "TeX Gyre Heros" cannot be found.
...
! Package fontspec Error: The font "Noto Serif CJK SC" cannot be found.

However, if I comment out the two lines with !!!, then it compiles.

With this A/B test I know that it is the recent (official) support of unicode-engine in newtx that breaks my code, because newtx uses fontspec now. I tried to pass [nofontspec] to newtx but the font turned out to be wrong.

What exactly is happening here? Any suggestions for fixing all my codes (I use newtx with fontspec heavily) without doing too much work?

Answer 1

I have observed the same problem with newpx and fontspec recently. See this question (and answer). I sent an e-mail to the author of newpx (and newtx) but didn't get an answer.

Add \defaultfontfeatures{} after loading newtx.

Answer 2

Unless you're strongly committed to pursuing the xeCJK approach, I'd like to suggest that you employ the unicode-math package and issue suitable \setmainfont, \setsansfont, and \setmathfont directives.

Since you're using the Noto Serif SC font family for the main (serif) text font, I wouldn't use Helvetica as the main sans-serif font. Instead, I'd employ the Noto Sans SC font family. If you must use a Times Roman clone as the math font, I'd ditch the newtxmath math font and, instead, issue the directive \setmathfont{Stix Two Math}.

I compiled the following code with MacTeX2022 and LuaLaTeX.

\documentclass[11pt]{article}
\usepackage{unicode-math}
\setmainfont{Noto Serif SC}
\setsansfont{Noto Sans SC}[Scale=MatchLowercase]
\setmathfont{Stix Two Math}[Scale=MatchLowercase]

\begin{document}
Test serif font. 

\textsf{Test sans-serif.} 

$x^2+y^2=z^2$.

测试中文。\quad \textsf{测试中文。}
\end{document}