qmake generates dependencies for a UI file as part of the rule for UIC compilation. qmake generates the dependency with no path info (relative or absolute) even if the header file (in the UI file) is in a different folder

In 5.9 it generates the full path.

uic -d list relative (and correct paths).

moc does it right as before.

Example:

<header>GEditor.h</header>

uic -d:

../../core/ang_gui/GEditor.h

Makefile in Qt 5.9:

/Users/david/software/core/ang_gui/GEditor.h

Makefile in Qt 5.12:

GEditor.h