Re: programming error: cyclic dependency: example

On Fri, 2025-08-29 at 06:45 +0000, Werner LEMBERG wrote:
> > The score below has the Bar_number_engraver moved to Staff level:
> 
> > depending on the details of the music this causes an error:
> 
> > 
> 
> > programming error: cyclic dependency:
> 
> >    calculation-in-progress encountered for
> > VerticalAxisGroup.adjacent-pure-heights
> 
> >    continuing, cross fingers
> 
> > 
> 
> > In the real-life example that lead to this MWE the typesetting is
> 
> > ok, so I'm submitting this in the hope it may prove useful for
> 
> > developers.  [...]
> 
> 
> Actually, I'm not surprised by the error message.  Your input code
> can
> be reduced to the following, also shown in the attached image.
> 
> ```
> \version "2.24.0"
> 
> <<
>   \new Staff { \stopStaff
>                f'1 | f'1 }
>   \new Staff { R1  | R1  }
> > > 
> 
> 
> \layout {
>   \context {
>     \Score
>     \remove Bar_number_engraver
>   }
>   \context {
>     \Staff
>     \consists Bar_number_engraver
>     \override BarNumber.break-visibility = #all-visible
>   }
> }
> ```
> 
> As can be seen, there are no bar lines available in the first staff,
> which are needed for the bar number engraver to vertically position a
> bar number. 
So ideally the bar number engraver could be written to not engrave a
bar number if there is no barline?
>  Of course, the error message is cryptic, and my
> interpretation might just be an educated guess – but I believe that a
> error message is OK for this situation.
I'm hoping so, but although there is an ly:expect-warning there doesn't
appear to be an ly:expect-error ...
> 
> What do you *really* want to achieve?
A good question - I'll open a new thread to address that on lilypond-
user, it will take a little work, but I think there may be some user
issues with ossia.
Thank you for the response
Richard Shann