BarNumber.whiteout over StaffGroup vertical lines

[Pierre-Luc Gauthier]

Hi there,

Not sure if this is a bug or if I am using it wrong.

I've started using :
\consists "Mark_engraver"
\consists "Bar_number_engraver"
, etc
inside StaffGroups since it is now working.
(Fixed with I think 622cab6a34 (Thanks to Dan Eble))

But I get a strange and inconsistent result with whiteouts of the
Bar_number_engraver.
The two images I've attached to this email are from a 400+ measures
score. Sometimes the bar number is in front of the vertical system
line and sometimes it is behind. I have not figured out what is
different in each case as it pops-up rather anywhere.

But! I have managed (by error) to "trigger" the behavior in the
following MWE might you {un,}comment line 4.

\version "2.21.0"

music = \repeat unfold 7 {c'4}
%music = \repeat unfold 8 {c'4}

\score {
  <<
    {s1 \break}
    \new StaffGroup \music
    \new StaffGroup \music
  >>
  \layout {
    \override Score.BarNumber.self-alignment-X = #CENTER
    \override Score.BarNumber.whiteout = #4
    \context {
      \Score
      \remove "Bar_number_engraver"
    }
    \context {
      \StaffGroup
      \consists "Bar_number_engraver"
    }
  }
}

Should a bug report be filed?

Thanks
-- 
Pierre-Luc Gauthier

BarNumberWhiteOut-02.png
Description: PNG image

BarNumberWhiteOut-01.png
Description: PNG image