I have come up with a way to run Xamarin.Mac in 64-bit mode. (The sources are available on GitHub if you’re interested.) As far as I can tell, making a Xamarin.Mac app work in 64-bit mode is as simple as recompiling Mono in 64-bit mode. However, the copy of Mono I built from source keeps crashing soon after launching. I think that Mono is misconfigured; however, there are so many
configure options that I can’t tell where the problem is.
My question is, how do you (and by “you” I mean Xamarin) build Mono as used in Xamarin.Mac? I need to rebuild it from source to make it run in 64-bit mode, but I also need as close to 100% compatibility with the Xamarin-shipped Mono as is possible. I feel a good place to start is configuring Mono the exact same way.
And by the way: I am only doing this until Xamarin ships 64-bit support natively. If Xamarin wants to borrow my technique to make Xamarin run in 64-bit mode, feel free!