[Python-modules-team] Bug#751460: ecdsa/util.py throws ImportException, cannot find "next" in python-six

[Michael Stapelberg]

Source: python-ecdsa
Version: 0.11-1
Severity: important

I use duplicity, which uses python-paramiko, which uses python-ecdsa
since version 1.14.0-1.

After upgrading to testing yesterday, duplicity does not work any
longer. This is the exception I get:

$ /usr/bin/duplicity list-current-files "$BASEPATH/root"                                                    
Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1495, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1489, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1323, in main
    action = commandline.ProcessCommandLine(sys.argv[1:])
  File "/usr/lib/python2.7/dist-packages/duplicity/commandline.py", line 1027, in ProcessCommandLine
    globals.backend = backend.get_backend(args[0])
  File "/usr/lib/python2.7/dist-packages/duplicity/backend.py", line 161, in get_backend
    return _backends[pu.scheme](pu)
  File "/usr/lib/python2.7/dist-packages/duplicity/backends/_ssh_paramiko.py", line 75, in __init__
    import paramiko
  File "/usr/lib/python2.7/dist-packages/paramiko/__init__.py", line 31, in <module>
    from paramiko.transport import SecurityOptions, Transport
  File "/usr/lib/python2.7/dist-packages/paramiko/transport.py", line 55, in <module>
    from paramiko.ecdsakey import ECDSAKey
  File "/usr/lib/python2.7/dist-packages/paramiko/ecdsakey.py", line 26, in <module>
    from ecdsa import SigningKey, VerifyingKey, der, curves
  File "/usr/lib/python2.7/dist-packages/ecdsa/__init__.py", line 3, in <module>
    from .keys import SigningKey, VerifyingKey, BadSignatureError, BadDigestError
  File "/usr/lib/python2.7/dist-packages/ecdsa/keys.py", line 5, in <module>
    from . import rfc6979
  File "/usr/lib/python2.7/dist-packages/ecdsa/rfc6979.py", line 14, in <module>
    from .util import number_to_string, number_to_string_crop
  File "/usr/lib/python2.7/dist-packages/ecdsa/util.py", line 9, in <module>
    from six import PY3, int2byte, b, next
ImportError: cannot import name next

There have not been recent changes in python-six, so I’m not sure how
python-ecdsa can ever have worked properly :).

Downgrading to python-paramiko 1.10.1-1 fixes the issue, as that version
is not using python-ecdsa at all.

Can you please take a look?

-- System Information:
Debian Release: jessie/sid
  APT prefers testing
  APT policy: (990, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: armel
i386

Kernel: Linux 3.14-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash