clef change confuses manual key signature

[james]

In the following:
\version "2.14.2"
\score {
   \relative c' {
      \time 2/4
      \set Staff.keySignature = #`(((0 . 4) . ,SHARP) ((0 . 3) . ,SHARP))
      \clef treble
      c8 a c d
%%% Commenting out the following line solves the problem %%%
      \clef bass
      e fis d c
   }
   \layout {}
}

The clef change causes lilypond to error and not produce output. This also 
errors in 2.15., while 2.12 does not error. Is there some way around this?