fretdiagram bug?

[bb]

I kindly ask the lilypond experts to check this code if I did a mistake or is it a bug?

Whatever I define in the line
\storePredefinedDiagram #default-fret-table \gSix
                        #allFourthsE
                        #"o,o,o,o,o"

lilypond will ignore!

Given is a questionable fretboard instead.

Please tell me where there is my error or if I should write a bug report.

Kind regards BB

START #####################

\version "2.19.2"

   allFourthsE =\stringTuning < e, a, d g c'>

gSix ={< e,\5 b'\4  d\3  g\2 d'\1 >1} %cegb

\storePredefinedDiagram #default-fret-table \gSix
                        #allFourthsE
                        #"o,o,o,o,o"

% end of potential include file /predefined-cuatro-fretboards.ly


%#(set-global-staff-size 27)

chordNames = \chordmode { g:6 }
notes = { \gSix \break  \bar "||" }
\score {
  <<
     \set Timing.defaultBarType = ""
     \new ChordNames {
      %\set chordChanges = ##t
      \chordNames
    }

    \new Staff {
        \clef "treble_8"
      \new Voice \with {
        \remove "New_fingering_engraver"
      }
      \relative c {
        \notes
      }
    }

    \new FretBoards {
      \set Staff.stringTunings = #allFourthsE
      \notes
    }

  >>

  \layout {
  }
}

END ################################