Testing Crates for 0.13.0 beta release(s)

[simlay]

Moving to use the objc2 crate is pretty cool. Speeds up compiler time substantially, removes the dependency on clang which has been broken by xcode updates - RustAudio/coreaudio-sys#79, RustAudio/coreaudio-sys#75, and RustAudio/coreaudio-sys#112.

These changes are pretty breaking but the main reverse dependency is cpal. The second most downloaded reverse dependency is riff-wave but hasn't been updated in 3 years and uses coreaudio-rs 0.5.

It seems that there are three active projects that use coreaudio-rs directly - cpa, surge-rs and aloe-rs.

So, using @madsmtm's PR to cpal - RustAudio/cpal#943, the dependents of cpal shouldn't have a breaking change but let's go through some testing of cpal`s reverse dependencies.

Here are the list of projects considered - checked means that it's either not applicable or I have test it:

• hound uses cpal 0.2.12 - released 9 years ago because it supports rust 1.40.
• https://github.com/RustAudio/rodio - tested various examples on macOS (aarch64). Tested noise_generation example with iOS sim (aarch64). Getting the example assets into the app via dinghy is more difficult than it should be.
• https://github.com/berkowski/tokio-serial I don't have the correct hardware to test this. I did compile it (for macos).
• bevy via bevy_audio - tested macOS (aarch64), iOS sim (aarch64), iOS (on device)
• https://github.com/tesselode/kira - audio example work great on macOS (big fan). All of the examples have assets so testing in iOS is problematic.
• https://github.com/amethyst/amethyst (repo archived)
• https://github.com/librespot-org/librespot - Patched with Fix compiler error when objc2 is in dependency tree librespot-org/librespot#1503
• https://github.com/orottier/web-audio-api-rs - Tested various examples on aarch64-apple-ios-sim (had to remove the resources directory for dinghy) and aarch64-apple-darwin
• https://github.com/SamiPerttu/fundsp - aarch64-apple-darwin works. Dev dependencies require eframe which depends on glutin and that does not support iOS targets (at least with the current version).
• https://github.com/ThomasHabets/rustradio - aarch64-apple-darwin, aarch64-apple-ios-sim and x86_64-apple-darwin works with the tone example.
• https://codeberg.org/sbechet/xmrsplayer - complies and runs for aarch64-apple-darwin but I don't have an XM or XmRs File for the example.

[simlay]

Huh. When working on current HEAD of librespot, when throwing in this patch:

diff --git a/Cargo.toml b/Cargo.toml
index ae89da4..faa47dc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -104,3 +104,6 @@ assets = [
 
 [workspace.package]
 rust-version = "1.81"
+
+[patch.crates-io]
+cpal = { git = "https://github.com/madsmtm/cpal", branch = "coreaudio-update" }

cargo build now says:

simlay@m1-mbp-si:~/projects/rust-audio/librespot (dev)$ cargo build
   Compiling librespot-connect v0.6.0-dev (/Users/simlay/projects/rust-audio/librespot/connect)
uerror[E0275]: overflow evaluating the requirement `&_: IntoIterator`
  --> connect/src/shuffle_vec.rs:65:56
   |
65 |         for (i, &rnd_ind) in (1..self.vec.len()).rev().zip(&indices) {
   |                                                        ^^^
   |
   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`librespot_connect`)
   = note: required for `&objc2::rc::retained::Retained<_>` to implement `IntoIterator`
   = note: 126 redundant requirements hidden
   = note: required for `&Retained<Retained<Retained<Retained<Retained<...>>>>>` to implement `IntoIterator`
   = note: the full name for the type has been written to '/Users/simlay/projects/rust-audio/librespot/target/debug/deps/librespot_connect-d7de9da5a372e7ea.long-type-1250449993922365444.txt'
   = note: consider using `--verbose` to print the full type name to the console

For more information about this error, try `rustc --explain E0275`.
error: could not compile `librespot-connect` (lib) due to 1 previous error

Following the recommendation, we need to do keep doubling the recursion limit until I get to #![recursion_limit = "2048"]. Once we get here, we get to this error:

simlay@m1-mbp-si:~/projects/rust-audio/librespot (dev)$ cargo build
    Blocking waiting for file lock on build directory
   Compiling librespot-connect v0.6.0-dev (/Users/simlay/projects/rust-audio/librespot/connect)
error: rustc interrupted by SIGBUS, printing backtrace

0   librustc_driver-82bda6a8a1496c15.dy 0x00000001106eb870 _RNvNtCs1qQ4FH5FMY4_17rustc_driver_impl14signal_handler17print_stack_trace + 140
1   libsystem_platform.dylib            0x000000019a6b8624 _sigtramp + 56
2   librustc_driver-82bda6a8a1496c15.dy 0x000000011214dec4 _RINvXsp_NtNtCs8wGzzH3abn_12rustc_middle2ty16structural_implsNtB8_2TyINtNtCs4JrQA9XOyKh_13rustc_type_ir4fold17TypeSuperFoldableNtNtB8_7context6TyCtxtE19try_super_fold_withNtNtNtCskqRMtimyJlt_11rustc_infer5infer7resolve24OpportunisticVarResolverECs8lEr7E81oSU_21rustc_trait_selection + 288

note: we would appreciate a report at https://github.com/rust-lang/rust
error: could not compile `librespot-connect` (lib)

Caused by:
  process didn't exit successfully: `/Users/simlay/.rustup/toolchains/stable-aarch64-apple-darwin/bin/rustc --crate-name librespot_connect --edition=2021 connect/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=245 --crate-type lib --emit=dep-info,metadata,link -C embed-bitcode=no -C debuginfo=2 -C split-debuginfo=unpacked --check-cfg 'cfg(docsrs,test)' --check-cfg 'cfg(feature, values())' -C metadata=8eb73079d95d8c3f -C extra-filename=-d7de9da5a372e7ea --out-dir /Users/simlay/projects/rust-audio/librespot/target/debug/deps -C incremental=/Users/simlay/projects/rust-audio/librespot/target/debug/incremental -L dependency=/Users/simlay/projects/rust-audio/librespot/target/debug/deps --extern futures_util=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/libfutures_util-6d6defc5ae0c2b01.rmeta --extern librespot_core=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/liblibrespot_core-e47a0d6b2f473df6.rmeta --extern librespot_playback=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/liblibrespot_playback-2d2e37ee793c59fa.rmeta --extern librespot_protocol=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/liblibrespot_protocol-0bbd8f2531996d87.rmeta --extern log=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/liblog-26ee380da5194fe7.rmeta --extern protobuf=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/libprotobuf-e413efaa858be2ad.rmeta --extern rand=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/librand-48d3b8e2dd69710b.rmeta --extern serde_json=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/libserde_json-a4e53f5ca631b513.rmeta --extern thiserror=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/libthiserror-27df129c3df03fb0.rmeta --extern tokio=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/libtokio-aee7ea8004d6302f.rmeta --extern tokio_stream=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/libtokio_stream-837fcad0eeeb958a.rmeta --extern uuid=/Users/simlay/projects/rust-audio/librespot/target/debug/deps/libuuid-41c4a9629b40eeb2.rmeta -L native=/Users/simlay/projects/rust-audio/librespot/target/debug/build/ring-6c20d1b4663c46a0/out -L native=/Users/simlay/projects/rust-audio/librespot/target/debug/build/aws-lc-sys-6bf41dd841d8677b/out` (signal: 10, SIGBUS: access to undefined memory)

[madsmtm]

Huh. That's odd.

I don't know why it wasn't failing before, but I think I can understand why it fails with that error; the type of indices seems very underspecified, they're trying to .collect(), but haven't specified the type that will be collected into.

The error seems to hint at something about objc2 having an impl IntoIterator for &Retained, which is somewhat unusual? People usually don't implement IntoIterator for references.

In any case, arguably very much a bug in librespot.

[madsmtm]

Narrowed it down to:
https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=e64a49420258b8fd87062955dd387898

[madsmtm]

It indeed seems like a combination of some undesired behaviour in rustc, and (therefore IMO) a bug in librespot.

[madsmtm]

Filed librespot-org/librespot#1503 for the librespot issue.