spanners not showing up

[Orm Finnendahl]

Hi,

 sorry, if that has been discussed before.

In the following example, there are two glissandos with an end arrow
between each f and g, but only the second one is showing up. This is
obviously due to lilypond's spacing decisions, not leaving enough
space for the first gliss sign (see attached png):

\version "2.14.2"

\relative c' {
  \time 6/4
      f'4 \glissando g4
      f2 \glissando g2 
}

\layout {
  \context { 
    \Voice
    \override Glissando #'(bound-details right arrow) = ##t
    \override Glissando #'arrow-length = #0.5
    \override Glissando #'arrow-width = #0.25
  }
}

My questions: 

1.: Is there a direct way to enforce lilypond to always print those
    signs and adjust its spacing accordingly (I'm aware that I could
    use a hidden second voice with eigth notes to enforce more
    horizontal space, but to me this seems more like a rather
    inelegant workaround than a solution)?

2.: Would it be possible to at least inform the user about the
    suppressed grob by printing a warning in the compilation buffer?


--
Orm

example-gliss.png
Description: PNG image