Release builds fail on macOS 27: Rust 1.95 strips proc-macro dylibs with misaligned __LINKEDIT (fixed in Rust 1.98) #8074

Summary

On macOS 27, cargo build --release of any crate that uses sqlx macros fails with the pinned Rust 1.95.0 toolchain. The cause is a known LLVM bug that is already fixed in Rust 1.98.0, so bumping rust-toolchain.toml to 1.98 or later resolves it. (#8049 upgrades the Hermit-managed tools but keeps the pin at 1.95.0.)

Reproduction

• macOS 27.2 (26B5091g), Xcode 27.0, arm64, at block/buzz main with the pinned toolchain:

$ cargo build --release -p buzz-db
error: …/libsqlx_macros-<hash>.dylib: dlopen(…): … mis-aligned LINKEDIT string pool, fileOffset=0x008730AC
error[E0432]: unresolved imports `self::encode::Encode`, …
error: could not compile `sqlx` (lib) due to 2 previous errors

• cargo check and tests pass, because the dev profile doesn't strip. Release builds of buzz-relay and anything else that depends on sqlx macros fail the same way.

Root cause

• Cargo's release profile defaults to strip = "debuginfo". On macOS, rustc strips with its bundled rust-objcopy (LLVM), not Apple's strip.
• LLVM's Mach-O objcopy wrote __LINKEDIT entries at offsets that are only 4-byte aligned, which macOS 27's dyld now rejects.
• Upstream reports and fixes:
  • Stripping debuginfo on macOS produces misaligned dylibs rust-lang/rust#157750
  • [llvm-objcopy][MachO] Stripping debug info from dylib produces misaligned __LINKEDIT entries llvm/llvm-project#203678, fixed by [llvm-objcopy][MachO] Align __LINKEDIT entries to pointer size llvm/llvm-project#203680
  • picked up in Update LLVM for Mach-O __LINKEDIT alignment fix. rust-lang/rust#158410, milestone 1.98.0

Checked on the same sqlx-macros dylib:

Small proc-macro dylibs often pass by luck of alignment, which is why a trivial repro may not trigger it. The sqlx-macros dylib Buzz builds (~12 MB, with Buzz's sqlx features) triggers it reliably.

Suggested fix

Bump rust-toolchain.toml to 1.98.0 or later (current stable is 1.99.0).

Until then, this workaround disables stripping only for build-time artifacts (proc macros, build scripts) and leaves shipped binaries unchanged:

CARGO_PROFILE_RELEASE_BUILD_OVERRIDE_STRIP=none cargo build --release

or

[profile.release.build-override]
strip = "none"