RSS Guard is a simple RSS/ATOM feed reader which can work with
RSS/ATOM/JSON/Sitemap feeds as well as many online feed services:
* Feedly
* Gmail
* Google Reader API (Bazqux, FreshRSS, Inoreader, Miniflux, Reedah,
  The Old Reader and more)
* Nextcloud News
* Tiny Tiny RSS

RSS Guard is also podcast player as it can play everything via its
built-in mpv-based (or ffmpeg-based) media player.

This Slackbuild will detect automatically the presence of Qt6 via
the QT6DIR environment variable. You may need to relog if you just
installed Qt6.
However that can be forced with BUILD_WITH_QT6=ON or OFF, allowing
to build for Qt5 when Qt6 is installed, or to fail building with
Qt6 if it is not present, should you want to try that.

There are also other parameters:
NO_LITE=ON : heavier version, able to display HTML through QT
NO_UPDATE_CHECK=ON : Don't check for updates, this is the job of SBo
ENABLE_COMPRESSED_SITEMAP=ON : allows understanding sitemap.xml.gz
And at most one multimedia backend:
ENABLE_MEDIAPLAYER_QTMULTIMEDIA=ON : Uses Slackware's ffmpeg
ENABLE_MEDIAPLAYER_LIBMPV=OFF : Requires the mpv packages from Sbo.