Same problem here:
sudo cowbuilder --create
-> Invoking pbuilder
forking: pbuilder create --buildplace /var/cache/pbuilder/base.cow --mirror
ftp://ftp.fu-berlin.de/pub/unix/linux/mirrors/debian --distribution sid
--no-targz --extrapackages cowdancer
I: Running in no-targz mode
I: Distribution is sid.
I: Building the build environment
I: running cdebootstrap
/usr/bin/cdebootstrap
P: Retrieving Release
P: Retrieving Release.gpg
P: Validating Release
I: Good signature from "Debian Archive Automatic Signing Key (4.0/etch)
<[email protected]>"
P: Parsing Release
P: Validating Packages.gz
P: Parsing Packages
P: Validating gcc-4.4-base
P: Validating libgcc1
P: Validating libc6
P: Validating libattr1
P: Validating libacl1
P: Validating libselinux1
P: Validating coreutils
P: Validating libstdc++6
P: Validating lzma
P: Validating dpkg
P: Validating perl-base
P: Validating liblocale-gettext-perl
P: Validating libtext-iconv-perl
P: Validating libtext-charwidth-perl
P: Validating libtext-wrapi18n-perl
P: Validating debconf-i18n
P: Validating debconf
P: Validating libpam-runtime
P: Validating libpam0g
P: Validating libdb4.7
P: Validating libpam-modules
P: Validating sensible-utils
P: Validating debianutils
P: Validating passwd
P: Validating adduser
P: Validating libbz2-1.0
P: Validating readline-common
P: Validating libncurses5
P: Validating libreadline5
P: Validating libusb-0.1-4
P: Validating zlib1g
P: Validating gpgv
P: Validating gnupg
P: Validating debian-archive-keyring
P: Validating apt
P: Validating apt-utils
P: Validating libncursesw5
P: Validating libsigc++-2.0-0c2a
P: Validating libcwidget3
P: Validating libxapian15
P: Validating libept0
P: Validating aptitude
P: Validating iproute
P: Validating mawk
P: Validating base-passwd
P: Validating base-files
P: Validating bash
P: Validating bsdutils
P: Validating bsdmainutils
P: Validating cpio
P: Validating sed
P: Validating ncurses-bin
P: Validating lsb-base
P: Validating cron
P: Validating dhcp3-common
P: Validating dhcp3-client
P: Validating diff
P: Validating dmidecode
P: Validating libcomerr2
P: Validating e2fslibs
P: Validating libuuid1
P: Validating libblkid1
P: Validating libss2
P: Validating e2fsprogs
P: Validating ed
P: Validating nano
P: Validating findutils
P: Validating gcc-4.2-base
P: Validating gcc-4.3-base
P: Validating grep
P: Validating groff-base
P: Validating gzip
P: Validating hostname
P: Validating net-tools
P: Validating ifupdown
P: Validating info
P: Validating mount
P: Validating libsepol1
P: Validating sysvinit-utils
P: Validating initscripts
P: Validating iptables
P: Validating iputils-ping
P: Validating libconsole
P: Validating libdb4.6
P: Validating libdevmapper1.02.1
P: Validating libgpg-error0
P: Validating libgcrypt11
P: Validating libgdbm3
P: Validating libtasn1-3
P: Validating libgnutls26
P: Validating libslang2
P: Validating libnewt0.52
P: Validating libpopt0
P: Validating libsasl2-2
P: Validating libssl0.9.8
P: Validating libusb-1.0-0
P: Validating libvolume-id1
P: Validating libwrap0
P: Validating rsyslog
P: Validating tzdata
P: Validating util-linux
P: Validating login
P: Validating logrotate
P: Validating man-db
P: Validating manpages
P: Validating mktemp
P: Validating module-init-tools
P: Validating ncurses-base
P: Validating netbase
P: Validating netcat-traditional
P: Validating procps
P: Validating sysv-rc
P: Validating sysvinit
P: Validating tar
P: Validating tasksel-data
P: Validating tasksel
P: Validating tcpd
P: Validating traceroute
P: Validating udev
P: Validating vim-common
P: Validating vim-tiny
P: Validating wget
P: Validating whiptail
P: Extracting gcc-4.4-base
P: Extracting libc6
P: Extracting libgcc1
P: Extracting libattr1
P: Extracting libacl1
P: Extracting libselinux1
P: Extracting coreutils
P: Extracting libstdc++6
P: Extracting lzma
P: Extracting dpkg
P: Extracting perl-base
P: Extracting liblocale-gettext-perl
P: Extracting libtext-iconv-perl
P: Extracting libtext-charwidth-perl
P: Extracting libtext-wrapi18n-perl
P: Extracting debconf
P: Extracting debconf-i18n
P: Extracting libpam-runtime
P: Extracting libpam0g
P: Extracting libdb4.7
P: Extracting libpam-modules
P: Extracting sensible-utils
P: Extracting debianutils
P: Extracting passwd
P: Extracting libncurses5
P: Extracting zlib1g
P: Extracting mawk
P: Extracting base-passwd
P: Extracting base-files
P: Extracting bash
P: Extracting bsdutils
P: Extracting sed
P: Extracting ncurses-bin
P: Extracting lsb-base
P: Extracting diff
P: Extracting libcomerr2
P: Extracting e2fslibs
P: Extracting libuuid1
P: Extracting libblkid1
E: Got signal: Broken pipe, cleaning up-- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]

