tl;dr: Does anyone know of a good reason as to why altering the SDK value of a Mach-O file is not a good idea.
I finally upgraded my development machine to macOS 10.14.6 (after several false starts, it claims it needed macOS 10.11.6, which I was running). Took about 4 hours to install.
The 2018r3 Xojo IDE just looks wrong on Mojave, if I switch between Light & Dark mode, I lose half the text in the IDE (because the IDE adjusts the text colors to enter dark mode, but not back again).
So I tried 2019r1.1 again. I had already tried it and reverted because it causes problems with one of my apps, but as I don't use that function in my other apps, I thought I'd be safe.
Sadly not, after about 15 minutes of use, I determined that there appears to be at least something wrong with how I convert Xojo doubles to NSNumbers as all graphics functions that do any kind of radial processing, are very very wrong. There's other visual issues with my apps.
This could take me a long time to figure out if there is a single root cause, or if there are multiple issues in the pipeline, maybe Apple changed something with CIKL, I don't know.
The version built with 2018r3 works as I would expect it to do.
The most obvious change is the SDK value in the Mach-O binary, App Wrapper knows where this is and could potentially set it back to 10.9 (which 2018r3) uses. However before I embark on this adventure, I wonder if anyone knows of a good reason as to why I shouldn't.
Actually using 10.14.6 instead of just for testing, man it's a buggy experience. System Preferences window jumps around when changing panels, controls appear disconnected from their pane and unusable (like half way up the window, with the top half just missing). How on earth did something so critical get pass QA testing?
Where has the sharing options for Facebook, Twitter & Flickr gone. My most used social media options gone, so now I need to write my own.
It also took me about 20 minutes to remove the plethora of iOS apps that I don't want or need from the machine. Not to mention that simply booting the machine consumes 12GB of 16GB of RAM, with about 500 little apps all running in the background. Just how many copies of mdworker actually need to be running, 8 seems excessive for a machine with a single user.
Man Apple have fallen far from the tree.