_cache->open() failed, please report.

[Roger Binns]

Binary package hint: update-manager

This is on a friend's mom's computer. When running update-manager it says:

E: dpkg was interrupted, you must manually run 'dpkg --configure -a' to correct the problem.
E: _cache->open() failed, please report.

There are several reports of this already in bugs, generally all closed as invalid. (eg #121930, #106690, #207684, #310735. #319926).

While the message may be meaningful to us technical folk, it is complete gibberish to normal users. It also neglects to mention that the command has to be run in a terminal and that it has to be prefixed by sudo (you can see the confusion in those other reports).

But even then this is silly. If the software wants the issue reported then it should report it itself. And since it knows exactly what command should be run to fix things, why not just run the command automatically?

And why is the situation even arising in the first place? The update system should handle it all gracefully in the first place. My best guess as to what happened is that the machine is set to automatically download and install updates. It was probably doing that when it was shutdown.

[Michele Mangili (mangilimic)]

Hello!

Thank you for taking the time to report this issue and helping to make Ubuntu better!

This problem doesn't directly belong to update-manager, but it seems to be a more general dpkg issue. I've found a comment in bug #323894 posted by Michael Vogt who wrote that such a kind of problems can be solved downloading a new version of dpkg from this archive: https://edge.launchpad.net/~mvo/+archive .

Could you please confirm that this workaround solves your issue? Thanks in advance

[Roger Binns (ubuntu-rogerbinns)]

I can't confirm that since instead I had to talk her through running terminal, sudo and the dpkg command over the phone which did fix it.

In any event bug #323894 is all about "dpkg --configure -a" not working. It did work just fine.

My complaint is about the message appearing in the first place and why the whole package/update system doesn't just self heal instead of spitting out a message that only the geekiest can understand. Also note that it is a security issue. The user's system was set to automatically update. She just ran the update manager out of curiosity to discover that she was over a hundred updates behind and the obscure message with the request to report it.

[Michele Mangili (mangilimic)]

Roger Binns wrote:
> My complaint is about the message appearing in the first place and why
> the whole package/update system doesn't just self heal instead of
> spitting out a message that only the geekiest can understand.

I understand your complaint. I think that this issue doesn't belong to
the update manager, but it should be handled by dpkg. As a matter of
fact update-manager uses dpkg in order to keep the system updated, and
the message you got was outputted by dpkg, not update-manager.

In many cases running 'dpkg --configure -a' doesn't solve the issue. For
example see bug #324252. For this reason I don't know if it is bug or a
feature of dpkg, however I agree that this message is almost
incomprehensible to an inexperienced user.

Anyway I'm not a developer of Ubuntu so... let's wait for a comment of a
more experienced user than me!

> Also note
> that it is a security issue. The user's system was set to automatically
> update. She just ran the update manager out of curiosity to discover
> that she was over a hundred updates behind and the obscure message with
> the request to report it.
>

On the other hand this issue should be handled by update-manager, which
may alert the user about missing updates.

For this reason I suggest you should change the description of this
report and ask to implement this missing feature in update-manager.

Thank you.

[Nikita Vetoshkin (nikita-vetoshkin)]

After today's update synaptics stopped woking with the same message.
Running sudo dpkg --configure -a doesn't help.

[Roger Binns (ubuntu-rogerbinns)]

Nikita, your problem is bug #324252.

This issue is that a problem occurs (it is irrelevant how), and that the packaging system knows the exact command to fix it, but instead of fixing it just gives up and gives a gibberish dialog to the user.

[Nikita Vetoshkin (nikita-vetoshkin)]

Roger that =)

[Alex Denvir (coldfff)]

We are closing this bug report because it has not been updated for some time. Please reopen it if you have more information to submit, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!

[Roger Binns (ubuntu-rogerbinns)]

It has not been updated because Ubuntu are just ignoring it. What is the point of bug reports if you are going to do nothing for over a year and then just close them?