bzr crashed with UnicodeEncodeError in mutter(): 'ascii' codec can't encode character u'\xe9' in position 28: ordinal not in range(128)

I was in the process of creating a *.deb with this command:

bzr dh_make mutt 1.4.2.3 mutt-1.4.2.3.tar.gz

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: bzr 2.4.1-1ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-16.28-generic 3.0.17
Uname: Linux 3.0.0-16-generic i686
ApportVersion: 1.23-0ubuntu4
Architecture: i386
BzrDebugFlags: set()
BzrVersion: 2.4.1
CommandLine: ['/usr/bin/bzr', 'dh_make', 'mutt', '1.4.2.3', 'mutt-1.4.2.3.tar.gz']
CrashDb: bzr
Date: Sat Feb 25 11:07:32 2012
ExecutablePath: /usr/bin/bzr
FileSystemEncoding: UTF-8
InstallationMedia: Kubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
InterpreterPath: /usr/bin/python2.7
Locale: fr_CH.UTF-8
PackageArchitecture: all
Platform: Linux-3.0.0-16-generic-i686-with-Ubuntu-11.10-oneiric
ProcCmdline: /usr/bin/python /usr/bin/bzr dh_make mutt 1.4.2.3 mutt-1.4.2.3.tar.gz
ProcEnviron:
 SHELL=/bin/bash
 LANG=fr_CH.UTF-8
 LANGUAGE=fr_CH:fr
PythonVersion: 2.7.2
SourcePackage: bzr
Title: bzr crashed with UnicodeEncodeError in mutter(): 'ascii' codec can't encode character u'\xe9' in position 28: ordinal not in range(128)
UpgradeStatus: No upgrade log present (probably fresh install)
UserEncoding: UTF-8
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare