XSLT error from f:description-string() during DTBook to EPUB3 conversion

What steps will reproduce the problem?
1. Run dtbook-to-epub3 with the attached DAISY input using a script such as 
this:

cli/dp2 dtbook-to-epub3 --i-source ./CK_12_Engineering__An_Introd.xml \
   --data /Users/john/testing/epub3/CK_12_Engineering_valid.zip \
   --file /Users/john/testing/epub3/CK_12_Engineering_valid-output.zip \
   --x-assert-valid false \
   > /Users/john/testing/epub3/CK_12_Engineering_valid-client.log

What is the expected output? What do you see instead?
Instead of a successful EPUB3 conversion, or even a job status of failure, I 
get a job failure and a web service internal failure message.

The client console output contains this at the end:

[WS] INFO(563) - Message:Conversion complete.
[WS] ERROR(564) - err:XTTE0790:An empty sequence is not allowed as the first 
argument of f:description-string()
[WS] ERROR(565) - An empty sequence is not allowed as the first argument of 
f:description-string()
[WS] ERROR(566) - An empty sequence is not allowed as the first argument of 
f:description-string()
[ERROR] WS Internal Failure:

No results available

What version of the product are you using? On what operating system?
Pipeline2 v1.6 on Ubuntu 12.04 or OS X 10.7

Please provide any additional information below.

Original issue reported on code.google.com by john.bru...@gmail.com on 28 Aug 2013 at 10:50

Attachments:

CK_12_Engineering_valid.zip

fatty- / daisy-pipeline

XSLT error from f:description-string() during DTBook to EPUB3 conversion #364