With Qt4 the release build target in the Makefile was dependent on the Makefile.Release and so on the Makefile itself. So if the .pro file changed, and the "nmake release" command was issued the Makefile and Makefile.Release was regenerated:
release: $(MAKEFILE).Release FORCE
$(MAKE) -f $(MAKEFILE).Release

With Qt5 (I only tried 5.3.2) this dependency is gone:
release: FORCE
@set MAKEFLAGS=$(MAKEFLAGS)
$(MAKE) -f $(MAKEFILE).Release

So if the .pro file changes the command "nmake release" does not trigger qmake to rebuild the Makefile.

This was handy for projects with many subdirectories, where "qmake -recursive" takes some time.

Is there a way to get this dependency back?

Thanks.