Without any error message, this bug took me too long to see:
Is line 18 actually a valid rule?
Thanks for the report. We’ll have a look.
I think this kind of lookup used to work? All three tonemark classes have five glyphs; I want either of Default or Narrow to be replaced by Small. Do I have to write [@laoSmallTonemarks @laoSmallTonemarks] as the replacement sequence now?
I would think that would be needed. In what version did that compile?