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.