cmake 3.19 has two possibly important changes

[Ken Cunningham]

https://cmake.org/cmake/help/latest/release/3.19.html#deprecated-and-removed-features

1. SDK search algorithm change: it will by default now find the newest SDK rather than prefer the system or deployment-target-matching SDK as it previously did.

The probably doesn’t affect many ports for us, as we set both  CMAKE_OSX_SYSROOT <https://github.com/macports/macports-ports/blob/daaac8a19bdf9cd60e3d208219233deb1ea4dc7c/_resources/port1.0/group/cmake-1.1.tcl#L435> , and also the SDKROOT, both of which, as belt-and-suspenders, should override cmake’s default SDK finding tricks.

2. SDKs prior to 10.5 are not supported.

I have no idea what this actually means in practice. So far, cmake 3.19 seems to be working as expected on Tiger…if it is a real issue I can roll back to 3.18.x on Tiger and then see about forward-porting whatever might be needed to make 3.19 work properly, if anything.

Ken