segfault in QTextEngine::shapeText after installing a new emoji font

When using the downstream program ibus-ui-emojier-plasma (an emoji picker tool, also known as the Plasma Desktop "emojier"), I got a segfault in QTextEngine::shapeText.

This happened immediately after installing to my local font directory the font "Twemoji Mozilla" and running fc-cache. The font is shipped with Firefox and you can get it from the latest Firefox binary download.

I don't see any segfaults when only Noto Color Emoji is installed.

The crash is repeatable. I'm attaching a backtrace I captured to this issue.

This issue might be related to https://bugreports.qt.io/browse/QTBUG-92358