pkg_postinst and pkg_postrm in the binary ebuild call
xdg_icon_cache_update and xdg_desktop_database_update, which
come from the xdg-utils eclass. Without `inherit xdg-utils`
those helpers are undefined and the hicolor icon cache never
refreshes on upgrade.
The source ebuild template (qbz.ebuild.template) already
inherits xdg, so this only affects users installing via
qbz-bin (the prebuilt binary path). The qbz-overlay has a
direct patch for v1.2.5; this ensures v1.2.6+ release-gentoo
runs emit correct ebuilds.
cc
vicrodh
931512fed3