"python setup.py test" complains that "test_suite must be a list"

[arch_o_median]

arc@showertimedepot:~/tahoe-darcs/tahoe$ python ./setup.py test
....
Running pycryptopp-0.5.15/setup.py -q bdist_egg --dist-dir /tmp/easy_install--gFcsx/pycryptopp-0.5.15/egg-dist-tmp-VM0Gi4
error: Setup script exited with error in pycryptopp setup command: test_suite must be a list

But version looks correct including pycryptopp: 0.5.15:

arc@showertimedepot:~/tahoe-darcs/tahoe$ ./bin/tahoe --version
allmydata-tahoe: 1.5.0-r4054, foolscap: 0.4.2, pycryptopp: 0.5.15, zfec: 1.4.5, Twisted: 8.2.0, Nevow: 0.9.33-r17222, zope.interface: 3.5.2, python: 2.5.2, platform: Linux-Ubuntu_8.10-x86_64-64bit_ELF, sqlite: 3.5.9, simplejson: 2.0.9, argparse: 1.0, pyOpenSSL: 0.7, pyutil: 1.4.1, zbase32: 1.1.1, setuptools: 0.6c12dev, pysqlite: 2.3.2