Assertion failure when overriding Stem.neutral-direction and having a second Voice
It appears to be impossible to use a Melody_engraver in a Voice that also includes a CueVoice. Here’s a LilyPond example that illustrates the issue:
\version "2.22.0" \new Voice \with { \consists "Melody_engraver" \override Stem.neutral-direction = #'() } { << { r } \new CueVoice { c'' } >> }
LilyPond outputs:
GNU LilyPond 2.22.0 Processing `test.ly' Parsing... Interpreting music... Preprocessing graphical objects... Finding the ideal number of pages... Fitting music on 1 page... Drawing systems...Assertion failed: (d == 1 || d == -1), function at, file /private/tmp/lilypond-20210130-26352-lkbhbf/lilypond-2.22.0/build/../flower/include/drul-array.hh, line 35.
\version "2.23.1"
\new Voice {
\override Stem.neutral-direction = #'()
<<
{ r }
\new Voice { c }
>>
}
Edited by Jonas Hahnfeld