After updating to Xcode 16.4, Package resolution fails with some cryptic errors. Each package fails with the following message Showing Recent Errors Only <unknown>:0: warning: legacy driver is now deprecated; consider avoiding specifying '-disallow-use-new-driver' <module-includes>:200:9: note: in file included from <module-includes>:200: 198 | #import "mach/mach_traps.h" 199 | #import "mach/mach_types.h" 200 | #import "mach/mach_vm.h" | `- note: in file included from <module-includes>:200: 201 | #import "mach/mach_voucher.h" 202 | #import "mach/mach_voucher_types.h" /Applications/Xcode-16.4.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.4.sdk/usr/include/mach/mach_vm.h:436:2: error: unknown type name 'mach_vm_offset_list_t'; did you mean 'mach_vm_offset_t'? 434 | ( 435 | vm_map_t target, 436 | mach_vm_offset_list_t in_pointer_list, | `- error: unknown type name 'mach_vm_offset_list_t'; did you mean 'mach_vm_offset_t'? 437 | mach_msg_type_number_t in_pointer_listCnt, 438 | mach_vm_offset_list_t out_pointer_list, /Applications/Xcode-16.4.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.4.sdk/usr/include/mach/arm/vm_types.h:108:33: note: 'mach_vm_offset_t' declared here 106 | 107 | typedef uint64_t mach_vm_address_t __kernel_ptr_semantics; 108 | typedef uint64_t mach_vm_offset_t __kernel_ptr_semantics; | `- note: 'mach_vm_offset_t' declared here 109 | typedef uint64_t mach_vm_size_t; 110 | <module-includes>:200:9: note: in file included from <module-includes>:200: 198 | #import "mach/mach_traps.h" 199 | #import "mach/mach_types.h" 200 | #import "mach/mach_vm.h" | `- note: in file included from <module-includes>:200: 201 | #import "mach/mach_voucher.h" 202 | #import "mach/mach_voucher_types.h" <unknown>:0: error: could not build Objective-C module 'Darwin' /Applications/Xcode-16.4.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.4.sdk/usr/include/mach/mach_vm.h:438:2: error: unknown type name 'mach_vm_offset_list_t'; did you mean 'mach_vm_offset_t'? 436 | mach_vm_offset_list_t in_pointer_list, 437 | mach_msg_type_number_t in_pointer_listCnt, 438 | mach_vm_offset_list_t out_pointer_list, | `- error: unknown type name 'mach_vm_offset_list_t'; did you mean 'mach_vm_offset_t'? 439 | mach_msg_type_number_t *out_pointer_listCnt 440 | ); /Applications/Xcode-16.4.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.4.sdk/usr/include/mach/arm/vm_types.h:108:33: note: 'mach_vm_offset_t' declared here 106 | 107 | typedef uint64_t mach_vm_address_t __kernel_ptr_semantics; 108 | typedef uint64_t mach_vm_offset_t __kernel_ptr_semantics; | `- note: 'mach_vm_offset_t' declared here 109 | typedef uint64_t mach_vm_size_t; 110 | /Users/paulwilliamson/Developer/ios-app/Packages/Modules/ModalAdvert/Package.swift:4:8: error: failed to build module 'PackageDescription' for importation due to the errors above; the textual interface may be broken by project issues or a compiler bug 2 | // The swift-tools-version declares the minimum version of Swift required to build this package. 3 | 4 | import PackageDescription | `- error: failed to build module 'PackageDescription' for importation due to the errors above; the textual interface may be broken by project issues or a compiler bug 5 | 6 | let package = Package( We don't specify -disallow-use-new-driver, so I'm unsure where that message comes from. We have cleared derived data and are performing a clean build.