Story with Mousetrap compiles into story which shows error message when opened

[Swidsno]

Ran twee2 build minerr.tw2 test.html --format=SugarCube2 (minerr here). The story contains Mousetrap 1.6.0, but doesn't assign any shortcuts.

Tested in Firefox, Chrome, and Konqueror. All show an error message starting with Apologies! An error has occurred. You may be able to continue, but some parts may not work properly., followed by:
Firefox: Error [tw-user-script-0]: nothing to repeat.
Chrome: Error [tw-user-script-0]: Unexpected token ].
Konqueror: Error [tw-user-script-0]: Invalid regular expression: nothing to repeat.

Story is otherwise functional. Assigning shortcut keys has no effect, but my best guess is that these are symptoms of the same issue.