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.

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% Take the A5 landscape dottes.pdf and produce a second PDF
% formatted for A4 portrait, which two pages per A4 page,
% and ordered for booklet printing.
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% Print the resulting PDF with long side duplex.
%
\documentclass[a4paper,final]{article}
\usepackage{pdfpages}
\usepackage{ifpdf,ifxetex}

\begin{document}
\includepdf[pages=-, nup=1x2, booklet=true]{dottesA5.pdf}
\end{document}