java ant says that 'Error: JAVA_HOME is not defined correctly.'

[i30817]

Building a uploaded java package that needs to run custom ant scripts to build on the server (packaging the libraries into a single jar kind of thing), gives this in i386:
https://launchpadlibrarian.net/130314200/buildlog_ubuntu-quantal-i386.bookjar_1.8.30_FAILEDTOBUILD.txt.gz
(failure, apparently because ant does not like the path of jdk).

But on amd64:
https://launchpadlibrarian.net/130315468/buildlog_ubuntu-quantal-amd64.bookjar_1.8.30_UPLOADING.txt.gz
(success)

Both builds were use this control file and come from the same source:
http://code.google.com/p/bookjar/source/browse/debian/control

I find this pretty strange. Am i using 'Architecture: any' incorrectly?

[i30817 (i30817)]

Might be a bug on update alternatives.

[William Grant (wgrant)]

Your i386 build is for some reason trying to run amd64 java:

Error: JAVA_HOME is not defined correctly.
  We cannot execute /usr/lib/jvm/java-7-openjdk-amd64/bin/java

[i30817 (i30817)]

Ugh never mind, problem between chair and keyboard.