0.4 recipes: bzr: ERROR: exceptions.AttributeError: 'cStringIO.StringI' object has no attribute 'split' [blocked on migration of PPAs to scalingstack]

When trying to build a recipe on Launchpad (~/tamersaadeh/bugzilla/bugzilla4), the build failed with that error. This also happened to 3 different build of the same recipe I tried.

Below is an excerpt from the failed oneiric build.

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 946, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 1150, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 699, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 721, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/cleanup.py", line 135, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/cleanup.py", line 165, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/builder/cmds.py", line 620, in run
    possible_transports=possible_transports)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/builder/cmds.py", line 463, in _get_prepared_branch_from_location
    changed = resolve_revisions(base_branch, if_changed_from=old_recipe)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/builder/recipe.py", line 653, in resolve_revisions
    if_changed_from=if_changed_from_revisions)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/builder/recipe.py", line 602, in _resolve_revisions_recurse
    substitute_branch_vars(new_branch.name, new_branch.branch, new_branch.revid)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/builder/recipe.py", line 1018, in substitute_branch_vars
    cl = changelog.Changelog(tree.get_file(cl_file_id))
  File "/var/lib/python-support/python2.5/debian_bundle/changelog.py", line 203, in __init__
    self.parse_changelog(file, max_blocks, allow_empty_author=allow_empty_author)
  File "/var/lib/python-support/python2.5/debian_bundle/changelog.py", line 222, in parse_changelog
    for line in self._file.split('\n'):
AttributeError: 'cStringIO.StringI' object has no attribute 'split'

bzr 2.4.0 on python 2.5.2 (Linux-2.6.24-29-xen-x86_64-with-debian-lenny-sid)
arguments: ['/usr/bin/bzr', 'dailydeb', '--safe', '--no-build', '/home/buildd
    /build-dac899605c5287e56d4f68d2c5d5f6cd89fb7bd4/chroot-
    autobuild/home/buildd/work/recipe', '/home/buildd/build-
    dac899605c5287e56d4f68d2c5d5f6cd89fb7bd4/chroot-
    autobuild/home/buildd/work/tree', '--manifest', '/home/buildd/build-
    dac899605c5287e56d4f68d2c5d5f6cd89fb7bd4/chroot-
    autobuild/home/buildd/work/tree/manifest', '--allow-fallback-to-native',
    '--append-version', '~oneiric1']
plugins: bash_completion[2.4.0], builder[0.7.2dev], changelog_merge[2.4.0],
    launchpad[2.4.0], netrc_credential_store[2.4.0], news_merge[2.4.0],
    weave_fmt[2.4.0]
encoding: 'ANSI_X3.4-1968', fsenc: 'ANSI_X3.4-1968', lang: None

*** 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.
(0.75604699999999991, 0.060002999999999994, 0, 0, 0, 0, 7602, 16, 0, 7176, 0, 0, 0, 0, 273, 63)
RUN: /usr/share/launchpad-buildd/slavebin/scan-for-processes ['/usr/share/launchpad-buildd/slavebin/scan-for-processes', 'dac899605c5287e56d4f68d2c5d5f6cd89fb7bd4']

Here are the links to the full logs of the failed builds:
1. https://launchpadlibrarian.net/89750689/buildlog.txt.gz (natty)
2. https://launchpadlibrarian.net/89750403/buildlog.txt.gz (oneiric)
3. https://launchpadlibrarian.net/89750503/buildlog.txt.gz (precise)