How do you align a TextSpanner with a RehearsalMark?

[Stefano Troncaro]

Hello everyone. The question is in the subject, example code:

\version "2.19.53"

\layout {
  \context {
    \Score
    \override RehearsalMark.self-alignment-X = #LEFT
    \override TextSpanner.to-barline = ##t
  }
}

\score {
  \new Staff {
    \relative c' {
      \override TextSpanner.bound-details.left.text = \markup { \teeny { "align with" } }
      c \startTextSpan d e f |
      g \stopTextSpan \mark "This" a b c |
    }
  }
}

How can you make the TextSpanner and the RehearsalMark objects aligned, in a similar way to how \< aligns with \f.