find_package(Qt6 COMPONENTS Core Qml CONFIG) marked Qml as a required component,
so any KDE package including ECMQmlModule failed its feature_summary even though
the module already returns gracefully when Qt6::Qml is absent. Use
OPTIONAL_COMPONENTS for Qml (Core stays required). qtdeclarative/QtQuick/QtQml
are not built for the Redox cross target; QML modules are simply skipped.
kf6-kcoreaddons 6.28.0 requires ECM >= 6.28.0 but the vendored ECM source/ was
still 6.10.0: the sync engine skipped it because ECM's version marker is a bare
set(VERSION "X.Y.Z") that the parser didn't recognize (only KF_VERSION /
PROJECT_VERSION / RELEASE_SERVICE_VERSION). Re-lay ECM from its 6.28.0 source.tar
(pure cmake modules, no Redox port) and teach both the sync engine and the
validator to read set(VERSION) so this class is caught, not silently skipped.
vasilito