LilyPond: auto horizontal space for dynamic text

Question

I am missing something basic, I spent hours searching for docs for no avail. Sometimes LilyPond can be really frustrating.

Look at this picture:

Obviously, ppp overlaps with the bar line. According to documentation, I tried using DynamicText.extra-spacing-width, but it has zero effect. Here's the code:

\version "2.22.1"
\language "italiano"

common = {
    \key sol \minor
    \time 4/4
    \tempo "Largo [Широко]"
}

right = \relative do'' {
    \key sol \major
    sol8 (fad re mi sol fad re4) |
    sol8 (fad re mib sol fad re4)
}

left = \relative do' {
    \key sol \major
    sol,8 (re' si' re,) sol, (re' do' re,) |
    sol, (re' sib' re,) sol, (re' do' re,) |
}

dynamics = {
    s1 |
    \override DynamicText.extra-spacing-width = #'(-1 . 1)
    s8 \ppp s8 s8 s8 s8 s8 s4
}

\score {
    \new PianoStaff <<
        \new Staff = "right" \right
        \new Dynamics \dynamics
        \new Staff = "left" { \clef bass \left }
    >>
}

If I move \override ... right in the front of \ppp, it doesn't overlap, but LilyPond complains then with "Unattached AbsoluteDynamicEvent".

Answer 1

I run into this a lot. I find that using an X-offset works:

dynamics = {
    s1 |
    \override DynamicText.X-offset = 0
    s8 \ppp s8 s8 s8 s8 s8 s4
}

Answer 2

This looks like a bug to me. For extra-spacing-width to work, both of the objects that should avoid each other must have some width and some height. You can visualize the "skylines" that LilyPond uses for distancing using

#(ly:set-option 'debug-skylines)
\layout {
  \context {
    \Score
    \override PaperColumn.stencil = #ly:separation-item::print
    \override NonMusicalPaperColumn.stencil = #ly:separation-item::print
  }
}

(it's expected that the ones from the lower staff are vertically off by some amount; horizontal skylines are built before line breaking, when we only have an estimation of the distance between the two staves).

This gives:

You can see that the problem is the SpanBar not receiving skylines; this is because it has no height, so the interval on which it is considered to collide is not known.

For now a workaround seems to be

\layout {
  \context {
    \Score
    \override SpanBar.Y-extent = #axis-group-interface::height
    \override SpanBar.meta.object-callbacks.pure-Y-common =
      #ly:axis-group-interface::calc-pure-y-common
    \override SpanBar.meta.object-callbacks.pure-relevant-grobs =
      #ly:axis-group-interface::calc-pure-relevant-grobs
  }
}

(there must be a reason why it is not in the current code, so be aware that it could have bad effects in cases that I have no considered).