Fonts with Em Size 1000 work fine (Fontforge: Element→Font Info→General→Em Size), but other values have size problems. In this case Adobe Arabic has the value 2048.
\documentclass{article}
\usepackage{harfload}
\usepackage{fontspec}
\setmainfont{AdobeArabic-Regular.otf}[RawFeature={mode=harf}]
\begin{document}
åäöüñÅÄÖÜÑ
اللُّغَة العَرَبِيّة هي أكثر اللغات تحدثاً ونطقاً
\end{document}
Git revisions 7657fe3 (harf) and e11c8e8 (harftex)
Fonts with Em Size 1000 work fine (Fontforge: Element→Font Info→General→Em Size), but other values have size problems. In this case Adobe Arabic has the value 2048.
Git revisions 7657fe3 (harf) and e11c8e8 (harftex)
./build.sh --tlopt="-C --with-system-cairo --with-system-freetype2 --with-system-gd --with-system-gmp --with-system-graphite --with-system-harfbuzz --with-system-icu --with-system-libpaper --with-system-libpng --with-system-mpfr --with-system-pixman --with-system-poppler --with-system-potrace --with-system-teckit --with-system-xpdf --with-system-zlib --with-system-zziplib --with-x-dvi-toolkit=xaw --build=x86_64-linuxmusl --host=x86_64-linuxmusl --target=x86_64-linuxmusl --datarootdir=/opt/texlive/2019 --prefix=/opt/texlive/2019 --bindir=/opt/texlive/2019/bin/ --libdir=/usr/lib --includedir=/usr/include --mandir=/usr/share/man --infodir=/usr/share/info --disable-native-texlive-build --enable-shared --disable-static --enable-largefile --disable-dependency-tracking --with-pic"