macOS 27: "rust-lld: error: could not load TAPI file"

I have rust-lld configured as my linker on macOS 27:

# ~/.cargo/config.toml

[target.aarch64-apple-darwin]
linker = "rust-lld"

Building anything spams a ton of linker errors like this:

error: linking with `rust-lld` failed: exit status: 1                                                                                                            
  |
  = note:  "rust-lld" "-flavor" "darwin" "[redacted]/target/debug/build/crc32fast-492ddc9329c1658b/rustcD8bsOM/symbols.o" "<2 object files omitted>" "<sysroot>/lib/rustlib/aarch64-apple-darwin/lib/{libstd-*,libpanic_unwind-*,libobject-*,libmemchr-*,libaddr2line-*,libgimli-*,libcfg_if-*,librustc_demangle-*,libstd_detect-*,libhashbrown-*,librustc_std_workspace_alloc-*,libminiz_oxide-*,libadler2-*,libunwind-*,liblibc-*,librustc_std_workspace_core-*,liballoc-*,libcore-*,libcompiler_builtins-*}.rlib" "-lSystem" "-lc" "-lm" "-arch" "arm64" "-platform_version" "macos" "11.0.0" "11.0.0" "-syslibroot" "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX27.0.sdk" "-o" "[redacted]/target/debug/build/crc32fast-492ddc9329c1658b/build_script_build-492ddc9329c1658b" "-dead_strip"
  = note: some arguments are omitted. use `--verbose` to show all linker arguments
  = note: rust-lld: error: could not load TAPI file at /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX27.0.sdk/usr/lib/libSystem.tbd: malformed file
          /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX27.0.sdk/usr/lib/libSystem.tbd:4:20: error: unknown architecture
                             arm64e.x1-macos, arm64e.x1-maccatalyst ]
                             ^~~~~~~~~~~~~~~

And none of the symbols can be found:

          rust-lld: error: undefined symbol: _memcpy
          >>> referenced by [redacted]/target/debug/build/crc32fast-492ddc9329c1658b/build_script_build-492ddc9329c1658b.build_script_build.7efdbd0b7c09a1c1-cgu.0.rcgu.o:(symbol __RINvMNtCs8Mbv00yxnRz_4core3stre5splitcECsaTYcvwnyYI7_18build_script_build+0x78)
          >>> referenced by [redacted]/target/debug/build/crc32fast-492ddc9329c1658b/build_script_build-492ddc9329c1658b.build_script_build.7efdbd0b7c09a1c1-cgu.0.rcgu.o:(symbol __RINvMNtCs8Mbv00yxnRz_4core3stre5splitcECsaTYcvwnyYI7_18build_script_build+0x58)
          >>> referenced by [redacted]/target/debug/build/crc32fast-492ddc9329c1658b/build_script_build-492ddc9329c1658b.build_script_build.7efdbd0b7c09a1c1-cgu.0.rcgu.o:(symbol __RINvMNtCs8Mbv00yxnRz_4core6optionINtB3_6OptionNtNtCs82bWklYMk3w_3std7process6OutputE8and_thenmNCNvCsaTYcvwnyYI7_18build_script_build19minor_rustc_version0EB1y_+0x50)
          >>> referenced 155 more times

Removing my global linker setting fixes builds.

This might be an upstream LLVM/lld issue, but I haven't found any similar reports.

Meta

rustc +stable --version --verbose:

rustc +stable --version --verbose                                                                  
rustc 1.98.1 (48a229cea 2026-09-01)
binary: rustc
commit-hash: 48a229ceaefd4985c50990b14116b6d856af0985
commit-date: 2026-09-01
host: aarch64-apple-darwin
release: 1.98.1
LLVM version: 22.1.8

rustc +nightly --version --verbose:

ustc 1.100.0-nightly (923c95cdf 2026-09-16)
binary: rustc
commit-hash: 923c95cdf5ba65cea505aa2ea829f578e1506ed8
commit-date: 2026-09-16
host: aarch64-apple-darwin
release: 1.100.0-nightly
LLVM version: 23.1.1

Reproduce on aarch64 macOS 27 using the ~/.cargo/config.toml rust-lld setting, then compare the failure with that setting removed. Investigate whether Rust or upstream LLVM/lld owns parsing the malformed libSystem.tbd TAPI entry. Done means identifying the responsible component and a confirmed fix or actionable upstream report.