qca2-plugin-gnupg version 2.0.0~beta3-1 failed to build in oneiric

qca2-plugin-gnupg version 2.0.0~beta3-1 failed to build in oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2709755

Details about the rebuild:
http://people.ubuntuwire.org/~wgrant/rebuild-ftbfs-test/test-rebuild-20110816-oneiric.html

Direct link to the build log: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2709755/+files/buildlog_ubuntu-oneiric-amd64.qca2-plugin-gnupg_2.0.0%7Ebeta3-1_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 690 lines into the build log:

dh_installdebconf -plibqca2-plugin-gnupg
dh_installemacsen -plibqca2-plugin-gnupg
dh_installcatalogs -plibqca2-plugin-gnupg
dh_installpam -plibqca2-plugin-gnupg
dh_installlogrotate -plibqca2-plugin-gnupg
dh_installlogcheck -plibqca2-plugin-gnupg
dh_installchangelogs -plibqca2-plugin-gnupg
dh_installudev -plibqca2-plugin-gnupg
dh_lintian -plibqca2-plugin-gnupg
dh_bugfiles -plibqca2-plugin-gnupg
dh_install -plibqca2-plugin-gnupg --sourcedir=debian/tmp
cp: cannot stat `debian/tmp/usr/lib/qt4/plugins/crypto/libqca-gnupg.so': No such file or directory
dh_install: cp -a debian/tmp/usr/lib/qt4/plugins/crypto/libqca-gnupg.so debian/libqca2-plugin-gnupg//usr/lib/qt4/plugins/crypto/ returned exit code 1
make: *** [binary-install/libqca2-plugin-gnupg] Error 2
dpkg-buildpackage: error: /usr/bin/fakeroot debian/rules binary-arch gave error exit status 2
******************************************************************************
Build finished at 20110823-0519
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/qca2-plugin-gnupg-2.0.0~beta3