bzr merge-package crashed with TypeError in _fetch_tarball(): 'NoneType' object is not iterable

[Evan Broder]

To reproduce:

bzr branch lp:debian/sid/freeimage
cd freeimage
bzr merge-upstream --version 3.15.1

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: bzr 2.4.1-1ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-13.22-generic 3.0.6
Uname: Linux 3.0.0-13-generic x86_64
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
BzrDebugFlags: set()
BzrVersion: 2.4.1
CheckboxSubmission: d27dbc9ce66475289526ca4b283ec487
CheckboxSystem: bb422ca46d02494cdbc459927a98bc2f
CommandLine: ['/usr/bin/bzr', 'merge-upstream', '--version', '3.15.1']
CrashDb: bzr
Date: Sat Dec 3 18:23:26 2011
ExecutablePath: /usr/bin/bzr
FileSystemEncoding: UTF-8
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
InterpreterPath: /usr/bin/python2.7
Locale: en_US.UTF-8
PackageArchitecture: all
Platform: Linux-3.0.0-13-generic-x86_64-with-Ubuntu-11.10-oneiric
ProcCmdline: /usr/bin/python /usr/bin/bzr merge-upstream --version 3.15.1
PythonVersion: 2.7.2
SourcePackage: bzr
Title: bzr crashed with TypeError in _fetch_tarball(): 'NoneType' object is not iterable
UpgradeStatus: Upgraded to oneiric on 2011-09-18 (76 days ago)
UserEncoding: UTF-8
UserGroups: adm admin cdrom dialout kvm libvirtd lpadmin plugdev sambashare sbuild

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #818093, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.