\language[main=ja] breaks \showframe

[ctrlcctrlv]

(This is a contrived example. By the time I discovered the problem, I realized frames are not a good solution to my problem. But, this is still a bug.)

\begin[class=book]{document}
\script[src=packages/frametricks]
\language[main=ja] % uncomment me to break everything
\begin[first-content-frame=tate1]{pagetemplate}
\frame[id=tate1,
left=left(content),right=right(content),bottom=top(content),next=content,height=40pt]
\end{pagetemplate}
\font[family=Noto Serif CJK JP]
\showframe
よくある質問（英語：FAQ）

よくある質問（英語：FAQ）

よくある質問（英語：FAQ）

楽しい答え（英語：FAQ）

楽しい答え（英語：FAQ）

楽しい答え（英語：FAQ）
\showframe
\end{document}

This is SILE v0.10.5
<showframe.tex>

Error detected:
	/usr/share/sile/core/libtexpdf-output.lua:151: attempt to index field 'nodes' (a nil value)
stack traceback:
	/usr/share/sile/core/libtexpdf-output.lua:151: in function 'debugFrame'
	/usr/share/sile/packages/frametricks.lua:149: in function '?'
	/usr/share/sile/core/sile.lua:284: in function 'call'
	/usr/share/sile/core/inputs-common.lua:65: in function 'process'
	/usr/share/sile/core/inputs-texlike.lua:164: in function 'process'
	/usr/share/sile/core/sile.lua:237: in function 'readFile'
	/usr/bin/sile:62: in function </usr/bin/sile:62>
	[C]: in function 'xpcall'
	/usr/bin/sile:62: in main chunk
	[C]: in ?

[alerque]

Thanks for the report, this is a bug for sure.

Just for your future convenience though you might want to use jbook instead of book for Japanese texts. Also you can use \showframe[id=all] to reveal all frame boundaries without calling it from inside each one. Even simpler you can call SILE with sile -d frames input.sil to enable frame debugging without adding anything to your documnet at all.