trouble updating 7.04 -> 7.10

[sean darcy]

TJ wrote:
> On Sat, 2009-02-28 at 17:06 -0500, sean darcy wrote:
> 
>>> It'll overwrite whatever is there.  And, of course, 
>>> us.archive.ubuntu.com does have feisty.
>>>
>> And, of course, us.archive.ubuntu.com does _NOT_ have feisty
> 
> 
> Sean, how about using a read-only file system to prevent the unwanted
> change?
> 
> *If* it doesn't cause do-release-upgrade to throw a wobbly this might
> work:
> 
> sudo -i
> 
> dd if=/dev/zero of=/tmp/sources.list.d bs=1024 count=2048
> losetup /dev/loop1 /tmp/sources.list.d 
> mkfs.ext2 /dev/loop1
> mkdir /mnt/apt
> mount /dev/loop1 /mnt/apt
> mv /etc/apt/sources.list.d/* /mnt/apt/
> 
> # make the changes to /mnt/apt/prerequists-sources.list
> 
> umount /mnt/apt
> mount -o ro /dev/loop1 /etc/apt/sources.list.d 
> 
> do-release-upgrade
> 
> # Obviously, at the end of the process, put things back as they were:
> 
> umount /etc/apt/sources.list.d
> mount /dev/loop1 /mnt/apt
> mv /mnt/apt/* /etc/apt/sources.list.d/
> umount /mnt/apt
> losetup -d /dev/loop1
> rm /tmp/sources.list.d
> 
> 
> 
Man - that is brilliant. And it shoulda worked, but it didn't :(

A fatal error occured
Please report this as a bug and include the files 
/var/log/dist-upgrade/main.log and /var/log/dist-upgrade/apt.log in your 
report. The upgrade aborts now.
Your original sources.list was saved in /etc/apt/sources.list.distUpgrade.
Traceback (most recent call last):

   File "/tmp/tmpjg9FjS/gutsy", line 59, in <module>
     app.run()

   File "/tmp/tmpjg9FjS/DistUpgradeControler.py", line 1346, in run
     self.fullUpgrade()

   File "/tmp/tmpjg9FjS/DistUpgradeControler.py", line 1251, in fullUpgrade
     if not self.getRequiredBackports():

   File "/tmp/tmpjg9FjS/DistUpgradeControler.py", line 1140, in 
getRequiredBackports
     outfile = 
open(os.path.join(apt_pkg.Config.FindDir("Dir::Etc::sourceparts"), 
sourceslistd), "w")

IOError: [Errno 30] Read-only file system: 
'/etc/apt/sources.list.d/prerequists-sources.list'


But it does show where the problem is.

Thanks for the suggestion.

sean