Updat wants to remove too much

[Teunis]

After the usual update & dist-upgrade I get the following:

The next packages will be REMOVED::
  build-essential g++ g++-4.9 google-earth-stable:i386 libc6-dev libstdc++-4.9-dev lsb-core nvidia-331
  nvidia-331-uvm ruby1.9.1-dev ruby1.9.1-full

This seems a little harsh on the system...

I don't understand the reason for this removal of important stuff....

[NickStone]

Are you upgrading from 14.04?

I have noticed with Debian and Debian based systems that when you upgrade to the next version by performing a "dist-upgrade" it wants to set up the new latest version as if you install it from scratch which means it will remove packages that are not default to the new version.

What you'll need to do is to re-install all the packages the dist-upgrade removes.

There is an alternative, you can move over to a rolling release distro such as Arch (or an Arch based distro) that way you'll get upgrades to all packages installed on your system without the system wanting to remove packages.

[oshunluvr]

sudo apt dist-upgrade isn't the same as do-release-upgrade. It's not a release change, just a full upgrade within the version:

dist-upgrade
dist-upgrade in addition to performing the function of upgrade,
also intelligently handles changing dependencies with new versions
of packages...

What's was being installed that pushed these packages out?

[NickStone]

sudo apt dist-upgrade isn't the same as do-release-upgrade. It's not a release change, just a full upgrade within the version:



What's was being installed that pushed these packages out?

After reading your comment I found this web page http://www.ghacks.net/2010/03/11/wha...on-of-apt-get/

The dist-upgrade option is quite different from upgrade. But just what does dist-upgrade do? Simple. The dist-upgrade option not only will upgrade all of the currently installed packages on your system it will also handle the dependency changes with new versions of packages. In other words, dist-upgrade will remove obsolete packages from your system, whereas upgrade will not. This function is out of necessity for upgrading from one distribution release to another.

and

Distribution upgrades are always tricky. I have had them go exceedingly well and I have had them go very awry. It's a gamble. But now you know exactly how to manage the task from the command line. You are now, officially, dangerous. ;-)

[oshunluvr]

Not sure what your point is Nick. I do nothing but dist-upgrade (to the point of aliasing "upgrade" to "sudo apt-get dist-upgrade") so that all needed changes occur when I upgrade packages. I've never done a distribution upgrade (preferring to do a full new install on my important machines) except once on a laptop that isn't needed daily and of the 1000's of times (not an exaggeration in the slightest) I've issued the dist-upgrade option to the apt-get command - none of those resulted in an unintended release change. Personally, I think the ghacks website you referenced (who are they, again?) mashes the real information in a confusing and misleading way. According to Ubuntu (we know who they are) https://help.ubuntu.com/community/AptGet/Howto dist-upgrade "The same as the above [referencing upgrade], except add the "smart upgrade" checkbox. It tells APT to use "smart" conflict resolution system, and it will attempt to upgrade the most important packages at the expense of less important ones if necessary." and then they follow with (emphasis added) ""apt-get dist-upgrade" does not perform distribution upgrade. See [http://www.ubuntu.com/getubuntu/upgrading] for more information." While I would agree that issuing a "dist-upgrade" prior to "do-release-upgrade" is an important step, doing "dist-upgrade" by itself is not indicative of a distribution upgrade.

I doubt that Teunis has unintentionally attempted a release upgrade. Rather, some package is mistakenly attempting to remove packages. I think we need more information to get to the bottom of this one...

[SteveRiley]

Syntax for the following discussion:

• P is a package
• v is a version number
• P=v is version v of package P (follows apt-get convention)

Say A depends on B. Currently, the system contains A=1 and B=5.

A month from now, A=2 is released, and it has the same dependencies. dist-upgrade will install A=2 over A=1 and all is well.

The following month, A=3 is released. This version incorporates routines from a newer version of B, so the package declares the dependency B=6 (in most cases, the actual declaration will be "greater than or equal to 6," but that's not relevant here). However, something about B prohibits muliple versions from being installed, so B contains a declaration that older versions conflict. dist-upgrade will evaluate this dependency chain and do three things: remove B=5, install B=6, install A=3.

Say the system also contains C. And C also has a dependency on B. In fact, the dependency claim is specifically for B=5. Now, the resolver is faced with a conundrum: since both B=5 and B=6 can't be present, what to do? Here is where APT's "importance evaluation" comes in. Following my example, if APT determines that A is more important than C, then dist-upgrade will not only remove B=5 but it will also remove C. When faced with this situation, APT actually interrupts itself and asks you what to do.

So that's the logic in play here. It would help to see the complete output of Teunis's dist-upgrade run, not just the quoted error.

I'll admit I've never found a satisfactory explanation for exactly how APT's "importance evaluation" process works.

[Teunis]

A new update solved the dependency problems.

Sorry for breaking your individual and collective brains on something that's in hindsight trivial.
Faced with such a problem I would always advice to wait a day for the repository to get 'with the times'.
But in this instance nothing had improved for about four days and using more than one repo, hence my post.

The problem seems to be at least partially caused by the extremely bad internet connection I'm having here in the North African Sahara, spotty and averaging below 28 K.
The message is now that the 283 MB of upgrade is going to take in excess of 4 hrs.

To come back to NickStone's suggestion, no, dist-upgrade has nothing to do with a distribution upgrade, it is just the common way to upgrade to the latest package versions, upgrade is rather more conservative.

Anyhow, I have to go as my class is waiting and the company's Win7 laptop only complains about a missing virus update.

[NickStone]

I stand corrected.

I normally use an Arch based distro, I find pacman much more easier to understand when it comes to upgrades. There's non of this upgrade; dist-upgrade or do-release-upgrade. To upgrade the entire system it's just pacman -Syu

[oshunluvr]

I stand corrected.

I normally use an Arch based distro, I find pacman much more easier to understand when it comes to upgrades. There's non of this upgrade; dist-upgrade or do-release-upgrade. To upgrade the entire system it's just pacman -Syu

I agree and think Yast is better too. Honestly I can't really understand why you would upgrade package A without upgrading B also, but there must have been a reason in some dev's mind.

@Teunis: I have seen this situation before and IME it's usually a missing package (repo not yet fully sync'd). Faced with this situation, I always give it 8-24 hrs and try again - that's usually all it takes...

[kubicle]

'apt-get upgrade' is a good option for automatic daily maintenance scripts, for example, as the risk for unexpected upgrade issues is very small (since no additional packages will be installed and no currently installed packages will be removed your system won't break because of dependency problems).

Of course you'll need to also run dist-upgrade manually from time to time to upgrade packages that are held back on just "upgrade" (so you can verify and accept required package installations and removals).

[oshunluvr]

That makes a lot of sense. Thanks...