Dist-upgrade to 10.04 fails

2010-11-17 11:56:13,447 INFO cache.commit()
2010-11-17 11:56:13,448 DEBUG failed to SystemUnLock() (E:Not locked)
2010-11-17 11:56:14,602 DEBUG fork pid is: 3654
2010-11-17 11:56:14,603 DEBUG fork pid is: 0
2010-11-17 13:01:42,777 ERROR got an error from dpkg for pkg: 'memtest86+': 'subprocess installed post-installation script returned error exit status 1
'
2010-11-17 13:01:42,777 DEBUG running apport_pkgfailure() memtest86+: subprocess installed post-installation script returned error exit status 1

2010-11-17 13:01:42,788 ERROR got an error from dpkg for pkg: 'memtest86+': 'subprocess installed post-installation script returned error exit status 1
'
2010-11-17 13:02:42,017 ERROR got an error from dpkg for pkg: 'ubuntu-standard': 'dependency problems - leaving unconfigured
'
2010-11-17 13:02:42,017 DEBUG running apport_pkgfailure() ubuntu-standard: dependency problems - leaving unconfigured

2010-11-17 13:02:42,017 ERROR got an error from dpkg for pkg: 'ubuntu-standard': 'dependency problems - leaving unconfigured
'
2010-11-17 13:02:51,395 ERROR got an error from dpkg for pkg: 'grub-pc': 'subprocess installed post-installation script returned error exit status 1
'
2010-11-17 13:02:51,396 DEBUG running apport_pkgfailure() grub-pc: subprocess installed post-installation script returned error exit status 1

2010-11-17 13:02:51,404 ERROR got an error from dpkg for pkg: 'grub-pc': 'subprocess installed post-installation script returned error exit status 1
'
2010-11-17 13:03:02,332 DEBUG got a conffile-prompt from dpkg for file: '/etc/netbeans.conf'
2010-11-17 13:10:20,109 ERROR Exception during pm.DoInstall()
Traceback (most recent call last):
  File "/tmp/tmpMTlREv/DistUpgradeView.py", line 182, in run
    res = pm.DoInstall(self.writefd)
SystemError: E:Sub-process /usr/bin/dpkg returned an error code (1)
2010-11-17 13:10:20,140 ERROR SystemError from cache.commit(): installArchives() failed
2010-11-17 13:10:20,141 DEBUG can't find apport

(I used the dist-upgrade tool which appeared in the system tray)

Further, then I clicked the button for continuing in the error-window which resulted in the error window disappearing and the "Distribution upgrade" window not responding to input anymore. Top shows that the CPU is idle so it's probably a deadlock.
No further logs were appended to main.log

FAIL =(

Fortunately, I got a full mirror backup of the affected system so I can roll-back to that and help you in debugging this by trying again after you've released fixed packages or told me how to fix it manually.

Notice that I tried to upgrade from Karmic, and all packages were up-to-date as of today.

update-manager-core package version is 1:0.126.10

memtest86+ upgrade probably fails because I manually replace one of it's files with a fixed version for amd64... I've undone this so the package should upgrade properly with my next attempt

However grub-pc fails because my Kubuntu is a NFS-booted one and there is no root device for grub.
grub-pc was NOT installed before the upgrade so it's installed automatically.

So the problem is probably caused by grub-pc not being aware of the standard NFS boot method which is described in ubuntu wikis...

I restored the backup of Kubuntu 9 and did the following modifications before trying to dist-upgrade again:

- Restored the original state of the memtest86+ package so upgrading it cannot fail
- As I've said when the problem occured first there was no grub installed before dist-upgrade and the dist-upgrade installed "grub-pc" due to dependencies and failed. So this time I tried to install "grub-pc" myself first and get it to configure properly which I was unable to because "grub-probe /" would always fail and the postinstall script depends on it. Therefore I gave up with "grub-pc" and installed the normal "grub" package which worked properly, maybe because its still the old grub and not grub2.

Then I tried to dist-upgrade again and it WORKED :) So the workaround for NFS-boot users is: Make sure that "grub" is installed, not "grub-pc".

Notice that my root filesystem is configured by fstab as /dev/nfs ... Therefore, the proper fix would be to make grub-probe recognize /dev/nfs as a valid root filesystem....