2020-05-12 23:40:56,016 INFO Using config files '['./DistUpgrade.cfg']'
2020-05-12 23:40:56,016 INFO uname information: 'Linux Nitro-AN515-51 5.3.0-51-generic #44-Ubuntu SMP Wed Apr 22 21:09:44 UTC 2020 x86_64'
2020-05-12 23:40:56,343 INFO apt version: '1.9.4'
2020-05-12 23:40:56,343 INFO python version: '3.7.5 (default, Apr 19 2020, 20:18:17) 
[GCC 9.2.1 20191008]'
2020-05-12 23:40:56,345 INFO release-upgrader version '20.04.19' started
2020-05-12 23:40:56,352 INFO locale: 'en_HK' 'UTF-8'
2020-05-12 23:40:56,414 INFO screen could not be run
2020-05-12 23:40:56,544 DEBUG Using 'DistUpgradeViewText' view
2020-05-12 23:40:56,611 DEBUG enable dpkg --force-overwrite
2020-05-12 23:40:56,653 DEBUG creating statefile: '/var/log/dist-upgrade/apt-clone_system_state.tar.gz'
2020-05-12 23:40:59,136 DEBUG lsb-release: 'eoan'
2020-05-12 23:40:59,137 DEBUG _pythonSymlinkCheck run
2020-05-12 23:40:59,141 DEBUG openCache()
2020-05-12 23:40:59,141 DEBUG quirks: running PreCacheOpen
2020-05-12 23:40:59,141 DEBUG running Quirks.PreCacheOpen
2020-05-12 23:40:59,634 DEBUG /openCache(), new cache size 91787
2020-05-12 23:40:59,635 DEBUG need_server_mode(): run in 'desktop' mode, (because of pkg 'ubuntu-desktop')
2020-05-12 23:40:59,635 DEBUG checkViewDepends()
2020-05-12 23:40:59,636 DEBUG running doUpdate() (showErrors=False)
2020-05-12 23:41:26,006 ERROR IOError/SystemError in cache.update(): ''. Retrying (currentRetry: 0)
2020-05-12 23:41:26,006 ERROR doUpdate() failed completely
2020-05-12 23:41:26,006 DEBUG openCache()
2020-05-12 23:41:26,516 DEBUG /openCache(), new cache size 91787
2020-05-12 23:41:26,516 DEBUG doPostInitialUpdate
2020-05-12 23:41:26,516 DEBUG quirks: running focalPostInitialUpdate
2020-05-12 23:41:26,516 DEBUG running Quirks.focalPostInitialUpdate
2020-05-12 23:41:31,443 DEBUG Snap core18 is installed
2020-05-12 23:41:32,257 DEBUG Snap gnome-3-34-1804 is installed
2020-05-12 23:41:32,257 DEBUG Snap gnome-3-34-1804 is not tracking the release channel
2020-05-12 23:41:32,682 DEBUG Snap gtk-common-themes is installed
2020-05-12 23:41:33,902 DEBUG Snap gnome-3-28-1804 is installed
2020-05-12 23:41:34,716 DEBUG Snap gnome-calculator is installed
2020-05-12 23:41:35,231 DEBUG Snap gnome-characters is installed
2020-05-12 23:41:36,037 DEBUG Snap gnome-logs is installed
2020-05-12 23:41:38,714 DEBUG MetaPkgs: ubuntu-desktop
2020-05-12 23:41:40,527 DEBUG Foreign: google-chrome-stable obs-studio
2020-05-12 23:41:40,527 DEBUG Obsolete: 
2020-05-12 23:41:40,528 DEBUG updateSourcesList()
2020-05-12 23:41:40,629 DEBUG rewriteSourcesList() with mirror_check
2020-05-12 23:41:40,629 DEBUG ['ubuntu-minimal', 'ubuntu-standard']
2020-05-12 23:41:40,629 DEBUG Checking pkg: ubuntu-minimal
2020-05-12 23:41:40,635 DEBUG Checking pkg: ubuntu-standard
2020-05-12 23:41:40,641 DEBUG examining: 'deb http://hk.archive.ubuntu.com/ubuntu/ eoan main restricted'
2020-05-12 23:41:40,641 DEBUG verifySourcesListEntry: deb http://hk.archive.ubuntu.com/ubuntu/ focal main restricted
2020-05-12 23:41:40,641 DEBUG url_downloadable: http://hk.archive.ubuntu.com/ubuntu//dists/focal/Release
2020-05-12 23:41:40,641 DEBUG s='http' n='hk.archive.ubuntu.com' p='/ubuntu//dists/focal/Release' q='' f=''
2020-05-12 23:43:50,810 DEBUG error from httplib: '<urlopen error [Errno 101] Network is unreachable>'
2020-05-12 23:43:50,810 DEBUG entry '# deb http://hk.archive.ubuntu.com/ubuntu/ eoan main restricted' was disabled (no Release file)
2020-05-12 23:43:50,811 DEBUG examining: 'deb http://hk.archive.ubuntu.com/ubuntu/ eoan-updates main restricted'
2020-05-12 23:43:50,811 DEBUG entry '# deb http://hk.archive.ubuntu.com/ubuntu/ eoan-updates main restricted' was disabled (no Release file)
2020-05-12 23:43:50,811 DEBUG examining: 'deb http://hk.archive.ubuntu.com/ubuntu/ eoan universe'
2020-05-12 23:43:50,811 DEBUG entry '# deb http://hk.archive.ubuntu.com/ubuntu/ eoan universe' was disabled (no Release file)
2020-05-12 23:43:50,811 DEBUG examining: 'deb http://hk.archive.ubuntu.com/ubuntu/ eoan-updates universe'
2020-05-12 23:43:50,812 DEBUG entry '# deb http://hk.archive.ubuntu.com/ubuntu/ eoan-updates universe' was disabled (no Release file)
2020-05-12 23:43:50,812 DEBUG examining: 'deb http://hk.archive.ubuntu.com/ubuntu/ eoan multiverse'
2020-05-12 23:43:50,812 DEBUG entry '# deb http://hk.archive.ubuntu.com/ubuntu/ eoan multiverse' was disabled (no Release file)
2020-05-12 23:43:50,812 DEBUG examining: 'deb http://hk.archive.ubuntu.com/ubuntu/ eoan-updates multiverse'
2020-05-12 23:43:50,812 DEBUG entry '# deb http://hk.archive.ubuntu.com/ubuntu/ eoan-updates multiverse' was disabled (no Release file)
2020-05-12 23:43:50,812 DEBUG examining: 'deb http://hk.archive.ubuntu.com/ubuntu/ eoan-backports main restricted universe multiverse'
2020-05-12 23:43:50,812 DEBUG entry '# deb http://hk.archive.ubuntu.com/ubuntu/ eoan-backports main restricted universe multiverse' was disabled (no Release file)
2020-05-12 23:43:50,813 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu eoan-security main restricted'
2020-05-12 23:43:50,813 DEBUG verifySourcesListEntry: deb http://security.ubuntu.com/ubuntu focal main restricted
2020-05-12 23:43:50,813 DEBUG url_downloadable: http://security.ubuntu.com/ubuntu/dists/focal/Release
2020-05-12 23:43:50,813 DEBUG s='http' n='security.ubuntu.com' p='/ubuntu/dists/focal/Release' q='' f=''
2020-05-12 23:43:51,825 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security main restricted' updated to new dist
2020-05-12 23:43:51,825 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu eoan-security universe'
2020-05-12 23:43:51,825 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security universe' updated to new dist
2020-05-12 23:43:51,826 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu eoan-security multiverse'
2020-05-12 23:43:51,826 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security multiverse' updated to new dist
2020-05-12 23:43:51,826 DEBUG examining: 'deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main'
2020-05-12 23:43:51,828 DEBUG entry '# deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main # disabled on upgrade to focal' was disabled (unknown mirror)
2020-05-12 23:43:51,828 DEBUG examining: 'deb http://ppa.launchpad.net/obsproject/obs-studio/ubuntu eoan main'
2020-05-12 23:43:51,830 DEBUG entry '# deb http://ppa.launchpad.net/obsproject/obs-studio/ubuntu focal main # disabled on upgrade to focal' was disabled (unknown mirror)
2020-05-12 23:44:18,740 DEBUG running doUpdate() (showErrors=True)
2020-05-12 23:44:28,062 DEBUG openCache()
2020-05-12 23:44:28,117 DEBUG /openCache(), new cache size 2361
2020-05-12 23:44:28,117 DEBUG need_server_mode(): run in 'desktop' mode, (because of pkg 'ubuntu-desktop')
2020-05-12 23:44:28,117 ERROR No 'ubuntu-minimal' available/downloadable after sources.list rewrite+update
2020-05-12 23:44:28,117 ERROR 'ubuntu-minimal' was not downloadable
2020-05-12 23:44:28,155 DEBUG abort called
2020-05-12 23:44:28,158 DEBUG openCache()
2020-05-12 23:44:32,006 DEBUG /openCache(), new cache size 91787