Subfiles 2.x broke \newfontfamily in subfile preamble

[Maia-Everett]

I have a subfile that defines and then uses a font family using the fontspec package, like this:

\documentclass[module]{subfiles}

\newfontfamily{\backpackfont}[
    Path=../fonts/Spectral/,
    Extension=.ttf,
    UprightFont=* Regular,
    BoldFont=* Bold,
    ItalicFont=* Italic,
    BoldItalicFont=* Bold Italic,
    Mapping=tex-text
]{Spectral}

\begin{document}
\clearpage

\chapter{Lorem Ipsum}

{
\backpackfont\fontsize{14}{18}\selectfont\addfontfeature{LetterSpace=0.5}\itshape

Some text...

}
\end{ddalspacing}

\end{document}

This works correctly with subfiles 1.6, but version 2.2 breaks it:

! Undefined control sequence.
l.20 \backpackfont
                  \fontsize{14}{18}\selectfont\addfontfeature{LetterSpace=0....
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

If I move the \newfontfamily command to the root .tex file, the document compiles correctly.

[Maia-Everett]

Looks like \newcommand in subfile preamble is now broken too. Is this intended behavior?

[gsalzer]

It is documented, so it is a feature, not a bug ;-) Let me guess: The problems occur when typesetting the main document that includes this file via \subfile, but it works when typesetting the subfile directly, right?

[gsalzer]

The default behavior since 2.0 is that the preamble is only processed when typesetting the subfile but is ignored when loading the subfile from the main file (together with \documentclass, \begin{document}, \end{document} and everything following \end{document}). These are the options:

• Load the subfiles package with the option v1, i.e., \usepackage[v1]{subfiles}. This will restore the behavior from older verions.
• Move the definitions from the 'preamble' (which isn't really a proper preamble) of the subfile after \begin{document}. Then they will be processed in any case.
• Move the definitions to the preamble of the main file.