Wubi installer crashed while installing amd64 natty (no /var/log/syslog or /var/log/partman available)

[Radu C]

- dual-boot along Win7
- wubi install (11.04-desktop-amd64) always crashes while "Checking for packages to remove..."
- message box:
"Installation failed
The installer encountered an unrecoverable error and will now reboot. [OK]"
- opened \ubuntu\disks\root.disk with ext2explore in Win7 after reboot, but there were no /var/log/syslog OR /var/log/partman files to be found inside the disk image.

after seeing current bug reports and guidelines, will retry the install using manual hard reset, see if I can retrieve any of the required log files, at all.

[Radu C (quarkshooter)]

could not retrieve logs; found them using Ctrl-Shift-F1 (via terminal) while error is on screen. need some way to copy logfiles to a safe place as they get deleted even on hard reset. might try to copy logfiles to filesystem root.

at the same time, found a workaround: unplugging the network cable seems to make Wubi/ubiquity skip over some steps which are responsible for this error.

yet, other errors pop up afterwards, see https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/825736

[bcbc (bcbc)]

Drop to terminal (CTRL+ALT+F2) and collect the logs (to \ubuntu\installation\logs.zip) by running:
sudo sh /host/ubuntu/install/custom-installation/hooks/failure-command.sh

[Radu C (quarkshooter)]

After some research, present bug [#825704] appears to be caused by some wubi-flavored variant of bug [#346386] - https://bugs.launchpad.net/ubuntu/+source/apt/+bug/346386.

Ubiquity tries to connect to ubuntu repositories during install. Because the local network does not permit internet access from any MAC address [DHCP via MAC address identification], wubi installer winds up being served a local router html page, with no access to the repositories. Wubi then probably tries to read said router html page as repository page, and outputs the error.

I have attached the error logs extracted as per @bcbc's instructions, thanks! :)

[bcbc (bcbc)]

Wubi doesn't need internet access to install. I do it regularly without it - so if you believe it's due to the router then just unplug your ethernet cable and don't try to connect your wireless during the install (if you have wireless). That will rule that out.

[bcbc (bcbc)]

PS just looked at the bug you referenced - that was fixed in Natty after it's release (will still be present on the release ISO), so it does seem a likely candidate for the problem.