Is this how Github actions and other CI services work? For some reason I thought they had to buy a bunch of Apple hardware ...
It is, but very weakly - basically a secret string stored in the SMI.
> Is this how Github actions and other CI services work? For some reason I thought they had to buy a bunch of Apple hardware ...
You can virtualize MacOS, but only on official Apple hardware. There is likely a fleet of Mac Pros or Mac Minis somewhere running real hardware + VMs.
EDIT: Read "You can ..." above as "You are authorized by Apple and can legally virtualize MacOS". You can run OSX on virtually any hardware in a VM, but doing it at scale or in a commercial setting will probably be a bad idea from a legal perspective.
Because it seems like you "can" in the technical sense (although I didn't try it, I looked at the code and it looks legit)
I imagine that a small CI service could start with the QEMU solution unofficially, but they would likely have to switch to Apple hardware before Apple got wind of it ...
legally only on apple hardware. It does actually work fine on normal PCs though.
Which, incidentally, is "ourhardworkbythesewordsguardedpleasedontsteal(c)AppleComputerInc"
https://www.rcfp.org/wp-content/uploads/imported/20120105_20...
(Direct link to PDF)