chord and chordChanges

[Gianmaria Lari]

Following code prints chord even if they don't change.

\version "2.21.0"

<<

  \new Staff   { 

    c'4 d' e' f'

    \repeat volta 2 {c' d' e' f' | g' a' b' c''}

  }

  \new ChordNames { 

    g1 \repeat volta 2 {g1|1}

  }

>>

To avoid to print chords always, I used \set chordChanges = ##t..... but  I would like to keep displaying the chord at the beginning of repeat. I tried this 

\version "2.21.0"

<<

  \new Staff   { 

    c'4 d' e' f'

    \repeat volta 2 {c' d' e' f' | g' a' b' c''}

  }

  \new ChordNames { 

    g1 \set chordChanges = ##t \repeat volta 2 {g1|1}

  }

>>

 

but obviously does not work. Is there any easy way to force lilypond print the chord in that case or I have to unroll the repeat etc. etc.?

Thank you, g.