Bob Gustafson wrote: > On Wed, 2009-04-15 at 09:38 -0500, Chris Adams wrote: >> Once upon a time, Bob Gustafson <bobgus@xxxxxxx> said: >>> Yes, I'm concerned about the ADDITIONAL packages removed by yum >>> because it does not maintain a reference count. >>> >>> It happened to me - 152 packages were removed. Many were critical to >>> the operation of my system. >>> A reference counting package manager would not have done that. >> What is this "reference counting" you keep mentioning? How would it >> have helped? >> >> You asked yum to do something, it displayed a list of all the actions it >> was going to take as a result, and you said yes. What else could it >> have done? >> >> When you tell yum to remove a package that other packages depend on, it >> can either remove all the dependencies, or not remove anything. >> Anything else leaves broken packages in the system. How would some >> "reference counting" change that? > > Suppose you have a package PkgA which requires libAB, libBB, libC > > On installation of PkgA, it finds that libAB and libBB are already > installed, having been installed with a previous package PkgB. It does > install libC. > > If you now remove PkgA, it finds that it depends on libAB, libBB, libC, > which it displays in a list for the user to decide whether it is ok to > also delete. If remove a application that depends on the library, the library itself will not be removed. > If the user says Yes, all of the packages PkgA, libAB, libBB, libC are > deleted, leaving the previously installed package PkgB with missing > libAB, libBB dependencies. This will never happen with Yum (or apt-get for that matter). If you try and remove a library that has both pkgA and pkgB as dependencies, both will be prompted for removal. Neither dep resolver will break a dep chain in the normal course of operations. Only way to do that in Fedora to force remove a package with rpm directly. > > A reference counting scheme would detect that libAB and libBB are also > used by another package and would not delete those two packages. Or > offer to delete them. This isn't how apt-get works really. The purpose of reference counting (or any other similar method to remove leaf dependencies) is to remove a library if it is no longer in use by any application. Rahul -- fedora-test-list mailing list fedora-test-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-test-list
