libparsetree-ruby version 3.0.5-1 failed to build in oneiric

libparsetree-ruby version 3.0.5-1 failed to build in oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2702435

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/2702435/+files/buildlog_ubuntu-oneiric-i386.libparsetree-ruby_3.0.5-1_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 577 lines into the build log:

applying patch 10_correct-path-for-ruby-interpreter to ./ ... ok.
applying patch 20_no-shebang to ./ ... ok.
applying patch 30_no-rubygems to ./ ... ok.
/usr/bin/make -f debian/rules update-config
make[1]: Entering directory `/build/buildd/libparsetree-ruby-3.0.5'
/usr/share/cdbs/1/rules/dpatch.mk:33: WARNING: dpatch.mk is deprecated - please use source format 3.0 (quilt) instead
make[1]: Nothing to be done for `update-config'.
make[1]: Leaving directory `/build/buildd/libparsetree-ruby-3.0.5'
touch debian/stamp-patched
# Run unit tests:
INLINEDIR=. /usr/bin/ruby1.8 -w -I lib:test:debian -r minitest/unit \
   -e 'Dir["test/test_*.rb"].each{|test| require test}'
. is insecure (40775). It may not be group or world writable. Exiting.
make: *** [build-stamp] Error 1
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110824-0442
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/libparsetree-ruby-3.0.5