Kindlegen is producing an error from titles

[reuven]

I run "rake deliverables", and get the following message from kindlegen:

Error(opfparser):E20006: There are more than one title defined in OPF metadata. 
But none of them is refined with "title-type" as "main" title. Refer 
http://idpf.org/epub/30/spec/epub30-publications.html#sec-opf-dctitle for more info.

My Rakefile contains the following:

  config.author              = "Reuven M. Lerner"
  config.title               = "Practice Makes Python"

Should I be setting the title elsewhere? Is there another parameter I should be setting? Is Kindlegen broken?

[avdi]

Interesting. This might actually be a new issue due to one of the tools changing (either kindlegen or pandoc, at a guess).

[avdi]

(This really highlights the need to get away from Pandoc for EPUB generation; there's just not enough control.)

[reuven]

If it's any help, here's what I have for pandoc:

$ pandoc --version
pandoc 1.12.3
Compiled with texmath 0.6.6.1, highlighting-kate 0.5.6.1.
Syntax highlighting is supported for the following languages:
    actionscript, ada, apache, asn1, asp, awk, bash, bibtex, boo, c, changelog,
    clojure, cmake, coffee, coldfusion, commonlisp, cpp, cs, css, curry, d,
    diff, djangotemplate, doxygen, doxygenlua, dtd, eiffel, email, erlang,
    fortran, fsharp, gnuassembler, go, haskell, haxe, html, ini, java, javadoc,
    javascript, json, jsp, julia, latex, lex, literatecurry, literatehaskell,
    lua, makefile, mandoc, markdown, matlab, maxima, metafont, mips, modelines,
    modula2, modula3, monobasic, nasm, noweb, objectivec, objectivecpp, ocaml,
    octave, pascal, perl, php, pike, postscript, prolog, python, r,
    relaxngcompact, restructuredtext, rhtml, roff, ruby, rust, scala, scheme,
    sci, sed, sgml, sql, sqlmysql, sqlpostgresql, tcl, texinfo, verilog, vhdl,
    xml, xorg, xslt, xul, yacc, yaml
Default user data directory: /Users/reuven/.pandoc
Copyright (C) 2006-2013 John MacFarlane
Web:  http://johnmacfarlane.net/pandoc
This is free software; see the source for copying conditions.  There is no
warranty, not even for merchantability or fitness for a particular purpose.

And for kindlegen:

*************************************************************
 Amazon kindlegen(MAC OSX) V2.9 build 0730-890adc2
 A command line e-book compiler
 Copyright Amazon.com and its Affiliates 2013
*************************************************************