This page describes changes to the 4.4.3 build system.
How Qt Extended uses pkg-config has been documented. The behavior has also been tweaked to avoid common problems.
Building for x86_64 now works.
Compatibility with pre-4.4.2 devices has been partially restored. Files in etc can live in their classic location (devices/device/etc) or in the new project-specific locations.
Install rules no longer process multiple files when a single file should be used (eg. when multiple real files map to the same solution path).