I was also bitten by this assert, in a score with divisi staves that appear/disappear depending on the VerticalAxisGroup.remove-layer settings (see http://lilypond.org/doc/v2.19/input/regression/a6/lily-436997bb.ly) which makes it nigh impossible to create a minimal example. I wouldn't be surprised to learn that a suppressed staff might trigger this assert, erroneously.
I downloaded 2.21 from git, commented out this assertion, and built. Everything is fine now. No other unexpected or orroneous behaviour which might have been caught by the assertion, in many projects. Sincere request: can this assert please be removed? Its validity appears debatable, and it is a showstopper for me! Rutger -- Sent from: http://lilypond.1069038.n5.nabble.com/Bugs-f58488.html _______________________________________________ bug-lilypond mailing list bug-lilypond@gnu.org https://lists.gnu.org/mailman/listinfo/bug-lilypond
