15.04 - nightly (21 March 15) - installer hangs after the 'prepare' section (doesn't get to 'Disk setup'

[yossarian_uk]

I tried to install Kubuntu 15.04 nightly AMD64 (21 March 2015)

The installer hangs after selecting '3rd party software' / 'Download updates while installing' - it doesn't get to 'Disk setup'

The 'workaround' is to cancel, start the installer again and it will get to disk setup and finish the install.

I have recreated the issue over 4 times, as soon as you cancel the next time it succeeds.

I hopefully have attached system logs , but here are the last 40 lines in syslog:-
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root@kubuntu:/home/kubuntu# tail -40 /var/log/syslog

Mar 21 21:08:34 kubuntu ubiquity: Setting up libquadmath0:amd64 (4.9.2-10ubuntu9) ...
Mar 21 21:08:34 kubuntu ubiquity: Setting up librsvg2-2:amd64 (2.40.8-1) ...
Mar 21 21:08:34 kubuntu ubiquity: Setting up libsignon-glib1 (1.12+15.04.20141209-0ubuntu1) ...
Mar 21 21:08:34 kubuntu ubiquity: Setting up libtsan0:amd64 (4.9.2-10ubuntu9) ...
Mar 21 21:08:34 kubuntu ubiquity: Setting up libubsan0:amd64 (4.9.2-10ubuntu9) ...
Mar 21 21:08:34 kubuntu ubiquity: Setting up liburl-dispatcher1:amd64 (0.1+15.04.20150123-0ubuntu1) ...
Mar 21 21:08:34 kubuntu ubiquity: Setting up libwacom-common (0.11+dfsg-0ubuntu1) ...
Mar 21 21:08:34 kubuntu ubiquity: Setting up libwacom2:amd64 (0.11+dfsg-0ubuntu1) ...
Mar 21 21:08:34 kubuntu ubiquity: Setting up lightdm (1.13.2-0ubuntu1) ...
Mar 21 21:08:34 kubuntu ubiquity: debconf: unable to initialize frontend: Dialog
Mar 21 21:08:34 kubuntu ubiquity: debconf: (TERM is not set, so the dialog frontend is not usable.)
Mar 21 21:08:34 kubuntu ubiquity: debconf: falling back to frontend: Readline
Mar 21 21:08:34 kubuntu ubiquity: debconf: unable to initialize frontend: Readline
Mar 21 21:08:34 kubuntu ubiquity: debconf: (This frontend requires a controlling tty.)
Mar 21 21:08:34 kubuntu ubiquity: debconf: falling back to frontend: Teletype
Mar 21 21:08:34 kubuntu ubiquity: Use of uninitialized value $template in exists at /usr/share/perl5/Debconf/Template.pm line 81, <GEN0> chunk 2.
Mar 21 21:08:34 kubuntu ubiquity: Use of uninitialized value $item in exists at /usr/share/perl5/Debconf/DbDriver/Cache.pm line 39, <GEN0> chunk 2.
Mar 21 21:08:34 kubuntu ubiquity: Use of uninitialized value $item in exists at /usr/share/perl5/Debconf/DbDriver/Cache.pm line 39, <GEN0> chunk 2.
Mar 21 21:08:34 kubuntu ubiquity: Configuring lightdm
Mar 21 21:08:34 kubuntu ubiquity: -------------------
Mar 21 21:08:34 kubuntu ubiquity:
Mar 21 21:08:34 kubuntu ubiquity: A display manager is a program that provides graphical login capabilities for
Mar 21 21:08:34 kubuntu ubiquity: the X Window System.
Mar 21 21:08:34 kubuntu ubiquity:
Mar 21 21:08:34 kubuntu ubiquity: Only one display manager can manage a given X server, but multiple display
Mar 21 21:08:34 kubuntu ubiquity: manager packages are installed. Please select which display manager should run
Mar 21 21:08:34 kubuntu ubiquity: by default.
Mar 21 21:08:34 kubuntu ubiquity:
Mar 21 21:08:34 kubuntu ubiquity: Multiple display managers can run simultaneously if they are configured to
Mar 21 21:08:34 kubuntu ubiquity: manage different servers; to achieve this, configure the display managers
Mar 21 21:08:34 kubuntu ubiquity: accordingly, edit each of their init scripts in /etc/init.d, and disable the
Mar 21 21:08:34 kubuntu ubiquity: check for a default display manager.
Mar 21 21:08:34 kubuntu ubiquity:
Mar 21 21:08:34 kubuntu ubiquity: 1. lightdm 2. sddm
Mar 21 21:08:34 kubuntu ubiquity:
Mar 21 21:08:34 kubuntu ubiquity: Default display manager:
Mar 21 21:17:01 kubuntu CRON[16471]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Mar 21 21:20:40 kubuntu systemd[1]: Starting Cleanup of Temporary Directories...
Mar 21 21:20:40 kubuntu systemd-tmpfiles[16474]: [/usr/lib/tmpfiles.d/var.conf:14] Duplicate line for path "/var/log", ignoring.
Mar 21 21:20:40 kubuntu systemd[1]: Started Cleanup of Temporary Directories.

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and last 40 lines in installer debug

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root@kubuntu:/home/kubuntu# tail -40 /var/log/installer/debug

Ubiquity 2.21.16
TEXT <small>If more than one person will use this computer, you can set up multiple accounts after installation.</small>
TEXT <small>Enter the same password twice, so that it can be checked for typing errors.</small>
TEXT <small>The name it uses when it talks to other computers.</small>
TEXT <small>If more than one person will use this computer, you can set up multiple accounts after installation.</small>
TEXT <small>Enter the same password twice, so that it can be checked for typing errors.</small>
TEXT <small>The name it uses when it talks to other computers.</small>
QSocketNotifier: Invalid socket 16 and type 'Read', disabling...
QSocketNotifier: Invalid socket 16 and type 'Exception', disabling...
QSocketNotifier: Invalid socket 16 and type 'Write', disabling...
Your console font configuration will be updated the next time your system
boots. If you want to update it now, run 'setupcon' from a virtual console.
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
update-initramfs is disabled since running on read-only media
debconf: DbDriver "passwords" warning: could not open /var/cache/debconf/passwords.dat: Permission denied
Ubiquity 2.21.16
QCoreApplication::postEvent: Unexpected null receiver
TEXT <small>If more than one person will use this computer, you can set up multiple accounts after installation.</small>
TEXT <small>Enter the same password twice, so that it can be checked for typing errors.</small>
TEXT <small>The name it uses when it talks to other computers.</small>
TEXT <small>If more than one person will use this computer, you can set up multiple accounts after installation.</small>
TEXT <small>Enter the same password twice, so that it can be checked for typing errors.</small>
TEXT <small>The name it uses when it talks to other computers.</small>
QSocketNotifier: Invalid socket 16 and type 'Read', disabling...
QSocketNotifier: Invalid socket 16 and type 'Exception', disabling...
QSocketNotifier: Invalid socket 16 and type 'Write', disabling...

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Thought id pass this on in case it helped the final release

(Plasma 5.2 is looking really nice !)

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: ubiquity-frontend-kde 2.21.16 [modified: usr/share/applications/kde4/ubiquity-kdeui.desktop]
ProcVersionSignature: Ubuntu 3.19.0-9.9-generic 3.19.1
Uname: Linux 3.19.0-9-generic x86_64
ApportVersion: 2.16.2-0ubuntu4
Architecture: amd64
CasperVersion: 1.355
CurrentDesktop: KDE
Date: Sat Mar 21 21:13:27 2015
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/kubuntu.seed boot=casper maybe-ubiquity quiet splash ---
LiveMediaBuild: Kubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150321)
PackageArchitecture: all
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)