Last time I checked meson still doesn't have great Qt support e.g. it can't track rcc dependencies [0]. Funnily enough that issue is about rcc not making dependencies available to the build system, but I believe it actually started doing so somewhere down the track. I did a little work on it a couple of years back but regrettably never followed up [1].

[0] https://github.com/mesonbuild/meson/blob/27c01dff01832fa9d0c... [1] https://github.com/mesonbuild/meson/issues/97#issuecomment-3...