Re: Vertical axis grob error

[David Nalesnik]

Hi Chris,

On Tue, Feb 10, 2015 at 5:44 PM, Chris Trahan <address@hidden> wrote:

One thing that I've found is than I an insert a \break and get the messages to stop.

[...]

 

The strange thing is that if I code it this way, the errors go away.

\repeat volta 3 {

   \repeat volta 2 {

      c d e f }

\alternative {

  { a b c d \break }

  { d c b a }
  }

  c d e f g a b c

}

OK, that's helpful.

The error you're seeing is thrown by Grob::get_vertical_axis_group_index in lily/grob.cc.  This is called in lily/span-bar-stub-engraver.cc and its Scheme version (ly:grob::get-vertical-axis-group-index) is called in scm/bar-line.scm.    In bar-line.scm, the Scheme function is called by ly:volta-bracket::calc-shorten-pair (which helps calculate placement of volta brackets relative to barlines).  I'm going to guess that this is something to do with voltas and barlines, perhaps barlines which span mutiple staves.

Is there any reason you can't enforce the break like you do above?  Or is this not an actual break in your song?

In any case, this error does not necessarily result from something you've done wrong.

HTH,

David