bzrtools version 2.4.0~bzr767-2ubuntu1 failed to build in oneiric

bzrtools version 2.4.0~bzr767-2ubuntu1 failed to build in oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2689767

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/2689767/+files/buildlog_ubuntu-oneiric-i386.bzrtools_2.4.0%7Ebzr767-2ubuntu1_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 870 lines into the build log:

    import graph
  File "/build/buildd/bzrtools-2.4.0~bzr767/graph.py", line 23, in <module>
    from bzrlib.deprecated_graph import node_distances, select_farthest
ImportError: No module named deprecated_graph
------------

----------------------------------------------------------------------
Ran 83 tests in 25.617s

FAILED (errors=1)
Missing feature 'bzrlib.plugins.bzrtools.zap.PipelinePluginFeature' skipped 3 tests.
make[1]: *** [override_dh_auto_test] Error 1
make[1]: Leaving directory `/build/buildd/bzrtools-2.4.0~bzr767'
make: *** [build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110817-0026
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/bzrtools-2.4.0~bzr767