so I assumed that you'd know if someone got it runing.
AFAIK nobody could make anything newer than 5.3 to work on 10.6
x86_64 (and situation is not much better for multiple later macOS). Qt is a badly written and horribly maintained software. Cocoa code cannot be built with gcc (for example, due to
this), so we have to wait until this
issue is fixed in gcc, and clang is broken altogether. An alternative, potentially, is X11 backend, which in principle could work, but it is broken for all macOS in all Qt versions, as I know (X11 add-ons might build, but I have not seen a standalone X11-based version for macOS). Qt5 also uses a borked build system, and to reach to fixing bugs in Qt itself it is needed to fix the former (I have a firm impression that it was designed to make life painful for anyone intending to sort out this mess). Qt6, thankfully, switched to CMake, but Qt6 assumes very recent SDK and uses Cocoa stuff from there, even when you try a Unix-like build. So I don’t know.
It is probably of little utility to fix an archaic version like 5.3 or 5.4, since pretty much everything requires a much newer Qt5. This leaves us with X11. And as of now, that does not work even on modern macOS, and perhaps was never tested by anyone.