do-release-upgradeエラー：「接続失敗」が10.04から12.04に更新されました
先週、10.04 LTSのいずれかを link （スクリーンツールの使用を除く）に厳密に従って12.04 LTSにアップグレードし、アップグレードが成功しました。同様に、別の10.04 LTSを12.04 LTSにアップグレードしようとすると、適切な更新/フェッチ中にエラーが発生し、画面にあるすべてをコピーして貼り付けることができません。 ssh経由でスクリーンショットを撮ることができましたが、ここで終了しました： 
以下はsources.listファイルです
#
# deb cdrom:[Ubuntu-Server 10.04.2 LTS _Lucid Lynx_ - Release i386 (20110211.1)]/ lucid main restricted
# deb cdrom:[Ubuntu-Server 10.04.2 LTS _Lucid Lynx_ - Release i386 (20110211.1)]/ lucid main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu/ lucid main restricted
deb-src http://archive.ubuntu.com/ubuntu/ lucid main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ lucid-updates main restricted
deb-src http://archive.ubuntu.com/ubuntu/ lucid-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu/ lucid universe
deb-src http://archive.ubuntu.com/ubuntu/ lucid universe
deb http://archive.ubuntu.com/ubuntu/ lucid-updates universe
deb-src http://archive.ubuntu.com/ubuntu/ lucid-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu/ lucid multiverse
deb-src http://archive.ubuntu.com/ubuntu/ lucid multiverse
deb http://archive.ubuntu.com/ubuntu/ lucid-updates multiverse
deb-src http://archive.ubuntu.com/ubuntu/ lucid-updates multiverse
## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu lucid partner
deb-src http://archive.canonical.com/ubuntu lucid partner
deb http://security.ubuntu.com/ubuntu lucid-security main restricted
deb-src http://security.ubuntu.com/ubuntu lucid-security main restricted
deb http://security.ubuntu.com/ubuntu lucid-security universe
deb-src http://security.ubuntu.com/ubuntu lucid-security universe
deb http://security.ubuntu.com/ubuntu lucid-security multiverse
deb-src http://security.ubuntu.com/ubuntu lucid-security multiverse
誰もこれを修正する方法を知っていますか？ありがとうございました！。
更新：1
Sources.listを別のソースに変更してみましたが、結果は同じです。
/var/log/dist-upgrade/main.log
2014-05-05 12:13:34,904 DEBUG Upgrade: Apache2 Apache2-mpm-prefork Apache2-utils Apache2.2-bin Apache2.2-common apparmor apparmor-utils apport apt apt-cacher apt-transport-https apt-utils aptitude avahi-daemon base-files bash bash-completion bind9-Host binutils bsdmainutils byobu bzip2 ca-certificates command-not-found command-not-found-data console-setup coreutils cpio cpp cpp-4.4 cpu-checker cron debianutils dhcp3-client dhcp3-common dnsutils dpkg dpkg-dev e2fslibs e2fsprogs elinks-lite file fontconfig-config friendly-recovery Fuse-utils g++ g++-4.4 gcc gcc-4.4 gcc-4.4-base gnupg gnupg-curl groff-base grub-common grub-pc icedtea-6-jre-cacao ifupdown info initscripts insserv installation-report iproute iptables iputils-arping iputils-ping kbd language-selector-common libacl1 libapache2-mod-Perl2 libapache2-mod-Perl2-dev libapache2-mod-php5 libapparmor-Perl libapparmor1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap libapt-inst1.4 libapt-pkg-Perl libapt-pkg4.12 libasound2 libatm1 libattr1 libauthen-pam-Perl libavahi-client3 libavahi-common3 libberkeleydb-Perl libblkid1 libbsd-resource-Perl libbsd0 libbz2-1.0 libc-bin libc-dev-bin libc6 libc6-dev libcap2 libcomerr2 libcups2 libcurl3 libcurl3-gnutls libcwidget3 libdb4.8 libdbd-mysql-Perl libdbi-Perl libdbus-1-3 libdbus-glib-1-2 libdrm-intel1 libdrm-radeon1 libdrm2 libedit2 libelf1 libexpat1 libexpat1-dev libflac8 libfontconfig1 libfontconfig1-dev libfreetype6 libfreetype6-dev libfuse2 libgcc1 libgcrypt11 libgd2-xpm libgdbm3 libgif4 libglib2.0-0 libgnutls26 libgomp1 libgpg-error0 libgpm2 libgssapi-krb5-2 libhtml-parser-Perl libice-dev libice6 libidn11 libio-interface-Perl libio-pty-Perl libjpeg62 libjpeg62-dev libk5crypto3 libkeyutils1 libkrb5-3 libkrb5support0 liblcms1 libldap-2.4-2 liblocale-gettext-Perl liblockfile1 libltdl7 libmagic1 libncurses5 libncursesw5 libnet-ssleay-Perl libnewt0.52 libnih-dbus1 libnih1 libnl1 libnspr4-0d libnss3-1d libogg0 libpam-modules libpam0g libparted0debian1 libpcap0.8 libpci3 libpcre3 libpcsclite1 libplymouth2 libpng12-0 libpng12-dev libpopt0 libpulse0 libreadline6 librpc-xml-Perl libsasl2-2 libsasl2-modules libselinux1 libsepol1 libsigc++-2.0-0c2a libslang2 libsm-dev libsm6 libsndfile1 libsqlite3-0 libss2 libssl0.9.8 libstdc++6 libstdc++6-4.4-dev libsub-name-Perl libtalloc2 libtasn1-3 libterm-readkey-Perl libtext-charwidth-Perl libtext-iconv-Perl libudev0 libusb-0.1-4 libuuid1 libvorbis0a libvorbisenc2 libwbclient0 libwrap0 libwww-curl-Perl libwww-Perl libx11-6 libx11-data libx11-dev libxau-dev libxau6 libxcb1 libxcb1-dev libxdmcp-dev libxdmcp6 libxext6 libxfont1 libxi6 libxml-libxml-Perl libxml-parser-Perl libxml-sax-Perl libxml2 libxmuu1 libxpm-dev libxpm4 libxrender1 libxt-dev libxt6 libxtst6 linux-generic-pae linux-headers-generic-pae linux-image-generic-pae locales logrotate lsb-release man-db module-init-tools mount mountall mysql-common mysql-server nano ncurses-bin net-tools ntfs-3g ntpdate odbcinst openjdk-6-jdk openjdk-6-jre openjdk-6-jre-headless openjdk-6-jre-lib openssh-client openssh-server openssl os-prober parted passwd pciutils Perl perl-base Perl-modules php-pear php5 php5-cli php5-common php5-curl php5-Gd php5-mysql pkg-config plymouth procps psmisc python python-apport python-apt python-dbus python-gdbm python-gnupginterface python-gobject python-httplib2 python-launchpadlib python-lazr.restfulclient python-lazr.uri python-minimal python-newt python-oauth python-openssl python-pam python-pexpect python-problem-report python-pycurl python-serial python-simplejson python-smartpm python-twisted-bin python-twisted-core python-wadllib python-zope.interface rsync rsyslog samba samba-common samba-common-bin Sudo sysvinit-utils tar tcpdump ubuntu-minimal udev ufw unixodbc update-manager-core update-notifier-common upstart ureadahead usbutils util-linux uuid-runtime vim vim-common vim-runtime vim-tiny w3m wget whiptail wireless-crda wireless-tools wpasupplicant x11proto-core-dev xfonts-utils xkb-data xz-utils zlib1g zlib1g-dev
2014-05-05 12:13:34,910 DEBUG apt btrfs snapshots supported: False
2014-05-05 12:13:34,910 DEBUG cache aufs_rw_dir: /tmp/
2014-05-05 12:13:34,911 DEBUG Free space on /: 42229010432
2014-05-05 12:13:34,911 DEBUG Dir /usr mounted on /
2014-05-05 12:13:34,912 DEBUG Dir /var mounted on /
2014-05-05 12:13:34,912 DEBUG Dir /boot mounted on /
2014-05-05 12:13:34,913 DEBUG Dir /var/cache/apt/archives mounted on /
2014-05-05 12:13:34,913 DEBUG Dir /tmp mounted on /
2014-05-05 12:13:34,914 DEBUG Dir /home mounted on /
2014-05-05 12:13:34,914 DEBUG Dir /tmp mounted on /
2014-05-05 12:13:34,914 DEBUG fs_free contains: '{'/var': <DistUpgradeCache.FreeSpace object at 0x91b53ac>, '/tmp': <DistUpgradeCache.FreeSpace object at 0x91b53ac>, '/usr': <DistUpgradeCache.FreeSpace object at 0x91b53ac>, '/boot': <DistUpgradeCache.FreeSpace object at 0x91b53ac>, '/home': <DistUpgradeCache.FreeSpace object at 0x91b53ac>, '/': <DistUpgradeCache.FreeSpace object at 0x91b53ac>, '/var/cache/apt/archives': <DistUpgradeCache.FreeSpace object at 0x91b53ac>}'
2014-05-05 12:13:35,540 DEBUG linux-image-3.2.0-61-generic-pae (new-install) added with 19135549 to boot space
2014-05-05 12:13:36,217 DEBUG dir '/var/cache/apt/archives' needs '76120226' of '<DistUpgradeCache.FreeSpace object at 0x91b53ac>' (42229010432.000000)
2014-05-05 12:13:36,220 DEBUG dir '/usr' needs '317531136' of '<DistUpgradeCache.FreeSpace object at 0x91b53ac>' (42152890206.000000)
2014-05-05 12:13:36,220 DEBUG dir '/usr' needs '52428800' of '<DistUpgradeCache.FreeSpace object at 0x91b53ac>' (41835359070.000000)
2014-05-05 12:13:36,220 DEBUG dir '/boot' needs '19135549' of '<DistUpgradeCache.FreeSpace object at 0x91b53ac>' (41782930270.000000)
2014-05-05 12:13:36,220 DEBUG dir '/tmp' needs '5242880' of '<DistUpgradeCache.FreeSpace object at 0x91b53ac>' (41763794721.000000)
2014-05-05 12:13:36,220 DEBUG dir '/' needs '10485760' of '<DistUpgradeCache.FreeSpace object at 0x91b53ac>' (41758551841.000000)
2014-05-05 12:13:36,221 DEBUG dir '/tmp' needs '0.0' of '<DistUpgradeCache.FreeSpace object at 0x91b53ac>' (41748066081.000000)
2014-05-05 12:13:36,221 DEBUG dir '/usr' needs '0.0' of '<DistUpgradeCache.FreeSpace object at 0x91b53ac>' (41748066081.000000)
2014-05-05 12:13:36,233 DEBUG demoted: 'python-smartpm python-central'
2014-05-05 12:13:36,233 DEBUG found components: {'precise': set(['restricted', 'main', 'multiverse', 'universe']), 'precise-security': set(['restricted', 'main', 'multiverse', 'universe']), 'precise-updates': set(['restricted', 'main', 'multiverse', 'universe'])}
2014-05-05 12:13:42,216 DEBUG abort called
2014-05-05 12:13:42,220 DEBUG openCache()
2014-05-05 12:13:42,220 DEBUG failed to SystemUnLock() (E:Not locked)
2014-05-05 12:13:44,763 DEBUG /openCache(), new cache size 31947
2014-05-05 12:13:44,772 DEBUG enabling apt cron job
lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.04.4 LTS
Release: 10.04
Codename: lucid
apt-getは、プロキシを使用するように設定し、プロキシ設定が間違っているか、プロキシが正しく機能していない（たとえば、インターネットにアクセスできない）場合にエラーを報告します。
/etc/apt/apt.confまたは/etc/apt/apt.conf.dのファイルのいずれかにプロキシが設定されているかどうかを確認します。
端末から確認する1つの方法は、apt-config dump|grep -i proxyを実行することです。