wasmtime / PR #8049 Replace `mach` dependency with `mach2` · git-wasmtime

Looks like the region PR for moving to mach2 has been open for several months: https://github.com/darfink/region-rs/pull/27 And worse the last release has been from over 2 years ago and once the current version gets released, it will lock the libc crate to version 0.2.107 from 2 years ago (for OpenBSD 6.9 support, which has been EOL since May 2022. libc presumably dropped support for it because it is EOL)

Wasmtime GitHub notifications bot (Mar 05 2024 at 17:35):

fitzgen commented on PR #8049:

@cfallin would you be up for fixing the aarch64 macOS build here? The last commit was too aggressive, and seems to have removed things that are still needed in mach2. The problem is I can't even do cargo check --target ... because I can't run the build scripts on my machine.

Wasmtime GitHub notifications bot (Mar 05 2024 at 17:42):

cfallin commented on PR #8049:

I can take a look, sure.

Wasmtime GitHub notifications bot (Mar 05 2024 at 18:10):

cfallin updated PR #8049.

Wasmtime GitHub notifications bot (Mar 05 2024 at 18:10):

cfallin updated PR #8049.

Wasmtime GitHub notifications bot (Mar 05 2024 at 18:12):

cfallin commented on PR #8049:

Pushed a fix; with this it cargo checks on macOS/aarch64. There's some weird inconsistency between the exception_behavior_t (a c_int) and the constants for the parameter (defined as c_uints); got a try_into/unwrap for now.

Wasmtime GitHub notifications bot (Mar 05 2024 at 18:12):

cfallin commented on PR #8049:

Ah, but with that there is a panic at that unwrap during a cargo test. Looking further.

Wasmtime GitHub notifications bot (Mar 05 2024 at 18:39):

cfallin updated PR #8049.

Wasmtime GitHub notifications bot (Mar 05 2024 at 18:41):

cfallin commented on PR #8049:

OK, so the issue (one issue anyway) is that MACH_EXCEPTION_CODES is defined as 0x8000_0000, which works great for its u32 type, but not the i32 type behind exception_behavior_t. I had hoped this was just a C-ism and tried an as cast to YOLO the signedness; that now runs into a SIGABRT on cargo test. This is officially Above My macOS Knowledge and needs someone else to look at it, I think!

Wasmtime GitHub notifications bot (Mar 06 2024 at 15:37):

alexcrichton commented on PR #8049:

Testing locally I'm seeing something that looks like it's running into this comment, namely the bindings for __Request__exception_raise_t are not aligned. I don't know if the bindings are right or what's going on here, but I vaguely remember seeing in the past another project define the type locally and use 64-bit values as well.

Wasmtime GitHub notifications bot (Mar 06 2024 at 15:37):

alexcrichton commented on PR #8049:

Notably the mach2 crate uses integer_t there, which is i32, not i64.

Wasmtime GitHub notifications bot (Mar 08 2024 at 05:36):

alexcrichton updated PR #8049.

Wasmtime GitHub notifications bot (Mar 08 2024 at 05:37):

alexcrichton commented on PR #8049:

I've pushed a commit which passes tests locally by copying over the copy of the struct that we have today and additionally queues up all tests to run in CI.

Wasmtime GitHub notifications bot (Mar 08 2024 at 05:42):

alexcrichton updated PR #8049.

Wasmtime GitHub notifications bot (Mar 08 2024 at 16:46):

alexcrichton merged PR #8049.

Last updated: Dec 13 2025 at 19:03 UTC