请尝试这个简单的代码：
\documentclass{article}
\usepackage{fontspec}
\usepackage[italian]{babel}
\babelfont{rm}[Numbers={Proportional,OldStyle},RawFeature=+pcap]{EB Garamond}
\newrobustcmd\lin[1]{{\addfontfeature{Numbers=Lining}#1}}
\newrobustcmd\textpc[1]{{\addfontfeature{Letters=PetiteCaps}#1}}
\begin{document}
\textsc{abcde fghijk lmnop qrstu vwxyz}
\textpc{abcde fghijk lmnop qrstu vwxyz}
\end{document}
Xelatex 生成 PetiteCaps，而 Lualatex 不生成。哪里出错了或者缺失了？RawFeature=+pcap 无关紧要。
谢谢
附言
在 Xelatex .log 中我读到：
Package fontspec Info: Font family 'EBGaramond(0)' created for font 'EB
(fontspec) Garamond' with options
(fontspec) [Ligatures=TeX,Script=Latin,Language=Italian,Numbers={Pr
oportional,OldStyle},RawFeature=+pcap].
(fontspec)
(fontspec) This font family consists of the following NFSS
(fontspec) series/shapes:
(fontspec)
(fontspec) - 'normal' (m/n) with NFSS spec.: <->"EB
(fontspec) Garamond/OT:script=latn;language=dflt;+pnum;+onum;+pcap;
mapping=tex-text;"
(fontspec) - 'small caps' (m/sc) with NFSS spec.: <->"EB
(fontspec) Garamond/OT:script=latn;language=dflt;+pnum;+onum;+smcp;
mapping=tex-text;"
(fontspec) - 'bold' (b/n) with NFSS spec.: <->"EB
(fontspec) Garamond/B/OT:script=latn;language=dflt;+pnum;+onum;+pca
p;mapping=tex-text;"
(fontspec) - 'bold small caps' (b/sc) with NFSS spec.: <->"EB
(fontspec) Garamond/B/OT:script=latn;language=dflt;+pnum;+onum;+smc
p;mapping=tex-text;"
(fontspec) - 'italic' (m/it) with NFSS spec.: <->"EB
(fontspec) Garamond/I/OT:script=latn;language=dflt;+pnum;+onum;+pca
p;mapping=tex-text;"
(fontspec) - 'italic small caps' (m/scit) with NFSS spec.: <->"EB
(fontspec) Garamond/I/OT:script=latn;language=dflt;+pnum;+onum;+smc
p;mapping=tex-text;"
(fontspec) - 'bold italic' (b/it) with NFSS spec.: <->"EB
(fontspec) Garamond/BI/OT:script=latn;language=dflt;+pnum;+onum;+pc
ap;mapping=tex-text;"
(fontspec) - 'bold italic small caps' (b/scit) with NFSS spec.:
(fontspec) <->"EB
(fontspec) Garamond/BI/OT:script=latn;language=dflt;+pnum;+onum;+sm
cp;mapping=tex-text;"
.
.
.
Requested font "EB Garamond/OT:script=latn;language=dflt;" at 10.00002pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-Regular.otf
Requested font "EB Garamond/BI/OT:script=latn;language=dflt;" at 10.00002pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-SemiBoldItalic.otf
Requested font "EB Garamond/OT:script=latn;language=dflt;" at 10.00002pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-Regular.otf
Requested font "EB Garamond/B/OT:script=latn;language=dflt;" at 10.00002pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-SemiBold.otf
Requested font "EB Garamond/OT:script=latn;language=dflt;" at 10.00002pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-Regular.otf
Requested font "EB Garamond/I/OT:script=latn;language=dflt;" at 10.00002pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-Italic.otf
Requested font "EB Garamond/OT:script=latn;language=dflt;" at 10.00003pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-Regular.otf
Requested font "EB Garamond/OT:script=latn;language=dflt;" at 10.00003pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-Regular.otf
Requested font "EB Garamond/B/OT:script=latn;language=dflt;" at 10.00003pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-SemiBold.otf
Requested font "EB Garamond/B/OT:script=latn;language=dflt;" at 10.00003pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-SemiBold.otf
Requested font "EB Garamond/I/OT:script=latn;language=dflt;" at 10.00003pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-Italic.otf
Requested font "EB Garamond/I/OT:script=latn;language=dflt;" at 10.00003pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-Italic.otf
Requested font "EB Garamond/BI/OT:script=latn;language=dflt;" at 10.00003pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-SemiBoldItalic.otf
Requested font "EB Garamond/BI/OT:script=latn;language=dflt;" at 10.00003pt
-> /usr/local/texlive/2021/texmf-dist/fonts/opentype/public/ebgaramond/EBGaram
ond-SemiBoldItalic.otf
相反，在 Lualatex .log 中我读到：
Package fontspec Warning: Language 'Italian' not available for font
(fontspec) 'EBGaramond' with script 'Latin'.
luaotfload | aux : font no 18 (nil) does not define feature pcap for script latn
with language dflt
Package fontspec Warning: OpenType feature 'Letters=PetiteCaps' (pcap) not
(fontspec) available for font 'EBGaramond' with script 'Latin'
(fontspec) and language 'Italian'.
luaotfload | aux : font no 23 (nil) does not define feature pcap for script latn
with language dflt