KDE Plasma 6.1.4 and Gear 24.05.2 Upgrade - 31/08/2024 00:00 GMT

Reasons
=======

KDE Plasma 5 has reached end of life and is no longer supported by Gentoo.
Qt5 upstream OSS support ended on 2020-12-08, and LTS releases - even with
considerable effort by KDE community's backports on top - only go so far.
It is therefore required for all users to upgrade to KDE Plasma 6[1].

At the same time, KDE Gear 24.05.2 is provided with most applications ported
over to KDE Frameworks 6. As long as KF5-based applications are being shipped
with the KDE Gear bundle, and other non-KDE Qt5-based applications still
common in ::gentoo repository, it is advised *not* to disable USE="qt5".


Changes
=======

Not many - much like Qt6, this is mostly an evolution of the existing
codebase, no disruptive feat.

Plasma Wayland support has come a long way and therefore KDE developers have
decided to make it the default login session for Plasma 6, even if some
known papercuts[2] remain. For users affected too much by those, switching
to the still existing X11 session is as easy as selecting it in the display
manager of choice. Disabling USE="wayland" is *not* changing this default,
it will yield no dependency savings, and we advise against doing so. It does
not affect users' X11 sessions.

In Gentoo:

The 32-bit ~arm/arm keyword was inconsistent across KDE Plasma, KDE
Frameworks, and KDE Gear, and has been dropped.

The situation for x86 was similar to arm and test failures often blocked
stabilization. Stable x86 has been dropped, ~x86 was dropped for KDE PIM,
dev-util/kdevelop and any other dev-qt/qtwebengine:6 reverse dependencies.


User Action Required
====================

For users of a desktop profile[3], no specific upgrade steps are necessary,
although some precautionary measures are advised before and during upgrade:

- Switch to a standard (Breeze or Oxygen) theme
- Depclean kde-misc/latte-dock, it is unfit for Plasma 6 (and masked already)
- Cleanup sets and @world from any SLOT or version pinning of KDE packages
- If possible, perform the upgrade not inside a running Plasma session

Necessary USE flag changes were already made in desktop profile, therefore
only users of other profiles should set USE="kf6compat qt6" globally[4].

Users are recommended to run the following command (pretend-only) to identify
packages in @world which have been removed, to help reduce conflicts:

    emerge -pev @world --backtrack=0

Then for any "no ebuild available" messages, either resolve it by making
the needed changes, or emerge --deselect them. Then proceed to the world
upgrade below.

Once the packages become available on your arch, it should be as simple as
update @world:

    emerge -avuUD @world

Run dispatch-conf (preferred) or etc-update to get updated configuration
files:

    dispatch-conf

Then depclean:

    emerge -ac

[1] https://kde.org/plasma-desktop/
[2] https://community.kde.org/Plasma/Wayland_Known_Significant_Issues
[3] https://wiki.gentoo.org/wiki/KDE#Profile
[4] https://wiki.gentoo.org/wiki//etc/portage/package.use