What does `emerge --update --newuse --deep @world` have to do with package removal?

In Debian-based distributions, one can update the system with apt upgrade and cleanup unused dependencies with apt autoremove. Period.

On Gentoo that is apparently not as straightforward. From Gentoo Cheat Sheet: Package removal:

The recommended way to remove a package is by using emerge --deselect. This removes the specified package from the @world set (i.e. says the package is no longer wanted). To clean up the system afterwards, run depclean as given below.

emerge --ask --depclean

As a safety measure, depclean will not remove any packages unless all required dependencies have been resolved. As a consequence of this, it often becomes necessary to run:

emerge --ask --verbose --update --newuse --deep @world

I understand emerge --deselect and emerge --depclean; Together they work as apt remove --autoremove.

I do not understand the last paragraph though. What does "depclean will not remove any packages unless all required dependencies have been resolved" mean exactly? Surely enough depclean won't remove dependencies currently in use. Why is it necessary to run the update command then? What does it have to do with package removal?

The Emerge manual was not of much enlightening here; It actually employs the very same wording.

posted over 2 years ago

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2y ago

Quasímodo‭

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