Some empty "" chords may be causing trouble with Jenkins. Jenkins builds are stalling when generating PDFs for some morris tunes. I suspect the problem may be an empty chord "" and abc2abc's attempt to transpose it. I've been meaning to remove the chords from the horn output, because abc2abc transposes them too, which renders them not terribly useful. So get on and do it. Also remove "" from the morris tunes where it occurs.

% Format for a graphic with a single tune
continueall false
measurenb false
writefields SRBDZHN 0
titleformat Y0
titlespace 0
topspace 0
infoline false
writehistory false
musiconly true
scale 0.9
botmargin 0pt
leftmargin 0pt
rightmarin 0pt
topmargin 0pt