ltxtest-platex-ng.log

$ platex-ng ltxtest
This is pTeX-ng, Version 3.14159265 (preloaded format=platex-ng)
entering extended mode
(ltxtest.tex
pLaTeX2e <2020-04-12u03> (based on LaTeX2e <2020-02-02> patch level 5)
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/ctexart.cls
(/usr/local/texlive/2020/texmf-dist/tex/latex/l3kernel/expl3.sty
(/usr/local/texlive/2020/texmf-dist/tex/latex/l3kernel/expl3-code.tex
(/usr/local/texlive/2020/texmf-dist/tex/latex/l3kernel/l3deprecation.def))
! Undefined control sequence.
<argument> \tex_shellescape:D 
                              
l.108   { \sys_load_backend:n { } }
                                   
? 

ltxtest-uplatex.log

$ uplatex ltxtest
This is e-upTeX, Version 3.14159265-p3.8.3-u1.26-191112-2.6 (utf8.uptex) (TeX Live 2020) (preloaded format=uplatex)
 restricted \write18 enabled.
entering extended mode
(./ltxtest.tex
pLaTeX2e <2020-04-12u03> (based on LaTeX2e <2020-02-02> patch level 5)
L3 programming layer <2020-04-06>
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/ctexart.cls
(/usr/local/texlive/2020/texmf-dist/tex/latex/l3kernel/expl3.sty
(/usr/local/texlive/2020/texmf-dist/tex/latex/l3backend/l3backend-dvips.def))
Document Class: ctexart 2019/05/29 v2.4.16 Chinese adapter for class article (C
TEX)
(/usr/local/texlive/2020/texmf-dist/tex/latex/l3packages/xparse/xparse.sty)
(/usr/local/texlive/2020/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty)
 (/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/ctexhook.sty)
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/ctexpatch.sty)
(/usr/local/texlive/2020/texmf-dist/tex/latex/base/fix-cm.sty
(/usr/local/texlive/2020/texmf-dist/tex/latex/base/ts1enc.def))
(/usr/local/texlive/2020/texmf-dist/tex/latex/ms/everysel.sty)
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/config/ctexopts.cfg)
(/usr/local/texlive/2020/texmf-dist/tex/latex/base/article.cls
Document Class: article 2019/12/20 v1.4l Standard LaTeX document class
(/usr/local/texlive/2020/texmf-dist/tex/latex/base/size10.clo))
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/engine/ctex-engine-uptex.def
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/fd/jt2zhrm.fd)
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/fd/jy2zhrm.fd)
(/usr/local/texlive/2020/texmf-dist/tex/latex/platex-tools/pxeverysel.sty)

Package ctex Warning: Functions of `CJKfntef' is not available in upLaTeX.

) (/usr/local/texlive/2020/texmf-dist/tex/latex/zhnumber/zhnumber.sty
(/usr/local/texlive/2020/texmf-dist/tex/latex/zhnumber/zhnumber-utf8.cfg))
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/scheme/ctex-scheme-chinese-a
rticle.def
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/config/ctex-name-utf8.cfg))
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/ctex-c5size.clo)
(/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/fontset/ctex-fontset-founder
.def)) (/usr/local/texlive/2020/texmf-dist/tex/latex/ctex/config/ctex.cfg)
No file ltxtest.aux.
ABD: EverySelectfont initializing macros

LaTeX Font Warning: Font shape `JY2/zhrm/m/sl' undefined
(Font)              using `JY2/zhrm/m/it' instead on input line 4.

[1] (./ltxtest.aux) )
Output written on ltxtest.dvi (1 page, 1144 bytes).
Transcript written on ltxtest.log.

ltxtest.tex

\documentclass[UTF8, fontset = founder]{ctexart}
\begin{document}
你好，\LaTeX{}。
\end{document}