`Package fontspec Warning: Font XXX does not contain requested Script "CJK"`, but visually it does

Question

I have below warning in LuaLaTeX/ltjsarticle project:

Package fontspec Warning: Font "fonts/HGS_Mincho/HGRMB.ttc" does not contain
requested Script "CJK".

I dot't know about Chinese and Korean, but Japanese language displaying correctly:

\documentclass[a4paper, twoside]{ltjsarticle}

\usepackage{luatexja-fontspec}

\edef\ProjectAbsolutePath{\directlua{tex.sprint((lfs.currentdir():gsub('\string\\', '/')))}/}

\setmainjfont[
  Path            = \ProjectAbsolutePath,
  UprightFont     = fonts/HGS_Mincho/HGRMB.ttc,
  BoldFont        = fonts/HGS_Mincho/HGRME.ttc,
  ItalicFont      = fonts/HGS_Mincho/HGRMB.ttc,
  BoldItalicFont  = fonts/HGS_Mincho/HGRME.ttc
]{HGS Mincho}

\setsansjfont[
  Path            = \ProjectAbsolutePath,
  UprightFont     = fonts/HGS_Gothic/HGRGM.ttc,
  BoldFont        = fonts/HGS_Gothic/HGRGE.ttc,
  ItalicFont      = fonts/HGS_Gothic/HGRGM.ttc,
  BoldItalicFont  = fonts/HGS_Gothic/HGRGE.ttc
]{HGS Gothic}


\begin{document}

\section{活字試験}

  \begin{itemize}
    \item 主要活字
    \begin{itemize}
      \item 漢あア
      \item \bfseries{漢あア}
    \end{itemize}
    \item ゴシック活字
    \begin{itemize}
      \item \textsf{漢あア}
      \item \textsf{\bfseries{漢あア}}
    \end{itemize}
  \end{itemize}
\end{document}

Why this warning appears and how I can correctly solve it?

Answer 1

You can manually specify the script with fontspec.

This should work (although I don't have the font to test).

\setmainjfont[
  Path            = \ProjectAbsolutePath,
  UprightFont     = fonts/HGS_Mincho/HGRMB.ttc,
  BoldFont        = fonts/HGS_Mincho/HGRME.ttc,
  ItalicFont      = fonts/HGS_Mincho/HGRMB.ttc,
  BoldItalicFont  = fonts/HGS_Mincho/HGRME.ttc,
  Script          = Default
]{HGS Mincho}

Update: Apparently, this font does not support a Default script either :(.

Therefore, the easiest option will be to suppress the warnings with fontspec. From §3.4 of the fontspec manual, passing quiet will put these warnings in the log file, and silent will suppress the warnings altogether.

\PassOptionsToPackage{quiet}{fontspec}% (or try silent)
\usepackage{luatexja-fontspec}