bzr fastexport stacktraces

[Scott Moser]

# fresh install / cloud instance
$ sudo apt-get update
$ sudo apt-get install --assume-yes --quiet bzr bzr-fastimport

$ bzr fast-export
bzr: ERROR: exceptions.ImportError: cannot import name binary_stream

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 930, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1121, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 673, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 697, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 136, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 166, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/fastimport/cmds.py", line 693, in run
    from bzrlib.plugins.fastimport import exporter
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/fastimport/exporter.py", line 67, in <module>
    from fastimport.helpers import (
ImportError: cannot import name binary_stream

bzr 2.7.0dev1 on python 2.7.8 (Linux-3.16.0-21-generic-x86_64-with-
    Ubuntu-14.10-utopic)
arguments: ['/usr/bin/bzr', 'fast-export']
plugins: bash_completion[2.7.0dev1], changelog_merge[2.7.0dev1],
    fastimport[0.13.0], grep[2.7.0dev1], launchpad[2.7.0dev1],
    netrc_credential_store[2.7.0dev1], news_merge[2.7.0dev1],
    po_merge[2.7.0dev1], weave_fmt[2.7.0dev1]
encoding: 'utf-8', fsenc: 'UTF-8', lang: 'en_US.UTF-8'

*** Bazaar has encountered an internal error. This probably indicates a
    bug in Bazaar. You can help us fix it by filing a bug report at
        https://bugs.launchpad.net/bzr/+filebug
    including this traceback and a description of the problem.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: bzr-fastimport 0.13.0-4
ProcVersionSignature: User Name 3.16.0-21.28-generic 3.16.4
Uname: Linux 3.16.0-21-generic x86_64
ApportVersion: 2.14.7-0ubuntu5
Architecture: amd64
Date: Wed Oct 8 16:16:41 2014
Ec2AMI: ami-000000af
Ec2AMIManifest: FIXME
Ec2AvailabilityZone: nova
Ec2InstanceType: m1.small
Ec2Kernel: aki-00000002
Ec2Ramdisk: ari-00000002
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: bzr-fastimport
UpgradeStatus: No upgrade log present (probably fresh install)

[Scott Moser (smoser)]

I don't really know why, but on trusty, this works:
 python -c 'from fastimport.helpers import binary_stream'

on utopic, it fails.