Clarification needed regarding removal of meta-packages

Hi folks.I have contributed to a couple of threads recently where advice has been sought by people about removing specific applications from the Ubuntu Mate desktop and where such removal has precipitated a warning from their system that the Ubuntu Mate meta-package would be removed in the process. I have hitherto been giving the advice that users would be advised to not try and remove a bundled app from a meta package and, instead, simply delete its menu entry and then just forget about it. Not because its removal will immediately break a person's system, but because it will have deliterious implications for any consequent upgrades to that system. The reason being that such upgrades are to the meta-package as a whole. But, following removal of a specific application from that meta-package, the meta-package (in it's original form) would cease to exist. See below for an official explanation I have lifted from the Ubuntu main site:

The first part appears to be saying that removal of a specific application or other dependancy within the meta package does not bring down the actual desktop. So far so good:

A metapackage, such as ubuntu-minimal or ubuntu-desktop, can have a long list of dependencies. So, when a metapackage is automatically removed by the removal or purging of any one, or more, of its underlying dependencies, all of the other packages that were in the metapackage's depends list are still installed on the system.

However, the second part appears to say that, although the desktop is not brought down, all subsequent upgrades are not going to work because they rely on upgrading the original (fully intact) meta-package. Obviously, if you have removed one or more of its dependancies, the original meta package no longer exists. However, if upgrading to a newer version of your desktop enironment, an upgrade becomes possible because the update-manager will check to see if you have any missing dependancies. In which case, presumably, it will reinstall them. Meaning, presumably, you will need to remove them again. Not so good:

If at a later time, there is an upgrade to the metapackage, the upgrade cannot occur, because the metapackage to be upgraded is no longer installed on the system. However when upgrading to new versions of Ubuntu the update-manager will check to see if you have the meta package installed before attempting to do an upgrade.

Finally, this article then seems to say that all of the above problems may be addressed to some extent by "some trickery". If all you are after is just a desktop environment that works and behaves itself, this is not good at all:

It may be possible to create a replacement metapackage to enable an upgrade, but some packages may then need to be removed or purged upon the upgrade of the metapackage. A metapackage which defines some Conflict or Replacement dependencies might be able to stop some of the unwanted packages from being reinstalled. Some trickery is needed.

All of which is why, as I mentioned at the start, my advice has always been to simply remove the menu entry for the application that is not wanted. Then simply ignore its presence on the system. After all, unless disk space is an absolute premium, it's not as if its continued presence is going to affect anything. Then, if the user wants, they may install whatever alternative they wish. Or no alternative at all, of course.

The reason I have brought all this up is because I have seen others giving the advice that it is absolutely unproblematic and inconsequential to remove applications from the meta package. I have asked those who have given this advice to clarify it in light of the above Ubuntu article. But I have recieved no response as yet. I fully accept this may be because I have completely misunderstood that article and there really are no upgrade implications of breaking a meta-package. But I would appreciate it if someone more knowledgable than me would confirm that is the case. Or, alternatively, confirm that there are indeed upgrade problems down the line. In which case, I will continue to give the same advice as previously.


Thanks for this clarification…I had no idea that this would affect my coming upgrade of a new UM release… in fact I did that removing twice while I was testing UM beta 2 release in March…and read that warning about removing dependencies from UM meta package…I had to do a clean install with UM official release just yesterday and so far it’s been working awesome…I will take your advice of removing the application I am not using in UM from the menu… as you said this is not affecting my hard drive space in any way.