Official Khronos MoltenVK releases
are incompatible with current osxcross versions due to Xcode automatically
using the -fobjc-msgsend-selector-stubs optimization.
The linker used by osxcross doesn't seem to support these yet, even when compiling against Apple LLVM.
See this upstream issue for details:
This repository simply does it own builds of MoltenVK with these flags added to disable the optimization:
-fno-objc-msgsend-selector-stubs -Wno-unused-command-line-argument
That's the only difference with Khronos' builds.