broken lyric example

[Graham Percival]

Could somebody check why this doesn't compile in 2.11.13 ?  It's the 
first example of "Lyrics to multiple notes of a melisma"
I'm suspicious about the multiple lyrics to the same context, but as far 
as I can see, nobody's changed this example in a while.


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  \relative \new Voice = "lahlah" {
    \set Staff.autoBeaming = ##f
    c4
    \slurDotted
    f8.[( g16])
    a4
  }
  \new Lyrics \lyricsto "lahlah" {
    more slow -- ly
  }
  \new Lyrics \lyricsto "lahlah" {
    \set ignoreMelismata = ##t % applies to "fas"
    go fas -- ter
    \unset ignoreMelismata
    still
  }
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