force specific Qt5 version install?

[Michael Dickens]

On my build computers, I have OSX 10.5 PPC and Intel 10.6 through 10.14; I'm still working on 10.4 PPC and 10.5 Intel (I don't think I have the partition space for 10.4 Intel, even if I wanted to install it, which I'm not sure I do). I am regularly struggling to get Qt5 to update and sometimes even install, especially on 10.10 through 10.13.

For example, right now on 10.13 I have Qt5 5.12.1 installed. "port" says that there is an update for qt5-qtbase and qt5-qtsvg ... to 5.11.3! Doing "sudo port upgrade outdated" fails because "port" can't figure out how to do the upgrade of the various Qt5 ports. [For the fun of it, I force uninstalled those ports (version 5.12.1) and then did "sudo port rev" and let "port" try to install the version of Qt5 it thinks is the correct version for this OS. I'm guessing once those ports at version 5.11.3 are installed, "port" will complain about ABI issues with the other Qt5 ports (which are at 5.12.1) ... we'll see!]

I see this Qt5 upgrade issue regularly, and usually "port" eventually figures out the correct version of Qt5 to install -- sometimes it takes some coercion, but after much ado I have a Qt5 working; I have no idea if it's truly the latest / best build for the OS, but "port" thinks so & thus I'm willing to go along with it.

Is there a way to force "port" to try to install a given Qt5 version? For example I know for a fact that 5.12.1 is buildable (and usable) on OSX 10.13 (since it was installed before this "update"), regardless of what "port" thinks.

Thanks for whatever thoughts y'all MacPorts developers have here! - MLD