Examples not building for OSX about rodio

[notryanb]

@tomaka I'd like to try and help with this issue, however I'm still pretty new to rust (especially rust concurrency). Currently reading through rodio, cpal, and coreaudio-rs libs. Any idea where I should try to focus my efforts?

[tomaka]

I'm not sure myself (haven't really looked yet).
Basically cpal forbids sharing something between threads (not sure exactly which object is concerned, and whether it is legitimate or not), while rodio tries to share it and fails.

[martinlindhe]

I hit the same error I guess (examples not building on macOS), but got a more verbose stack trace.

Posting it here in hope it is useful. If not, sorry for the noise.

rustc 1.24.0-nightly (1956d5535 2017-12-03), macOS 10.13.1

cargo run --example music_ogg

...
error[E0277]: the trait bound `for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static: std::marker::Send` is not satisfied
  --> src/engine.rs:35:18
   |
35 |                 .spawn({
   |                  ^^^^^ `for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static` cannot be sent between threads safely
   |
   = help: the trait `std::marker::Send` is not implemented for `for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static`
   = note: required because of the requirements on the impl of `std::marker::Send` for `&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static`
   = note: required because of the requirements on the impl of `std::marker::Send` for `std::ptr::Unique<&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static>`
   = note: required because it appears within the type `alloc::raw_vec::RawVec<&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static>`
   = note: required because it appears within the type `std::vec::Vec<&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static>`
   = note: required because of the requirements on the impl of `std::marker::Send` for `std::sync::Mutex<std::vec::Vec<&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static>>`
   = note: required because it appears within the type `cpal::cpal_impl::ActiveCallbacks`
   = note: required because of the requirements on the impl of `std::marker::Send` for `std::sync::Arc<cpal::cpal_impl::ActiveCallbacks>`
   = note: required because it appears within the type `cpal::cpal_impl::EventLoop`
   = note: required because it appears within the type `cpal::EventLoop`
   = note: required because it appears within the type `engine::Engine`
   = note: required because of the requirements on the impl of `std::marker::Send` for `std::sync::Arc<engine::Engine>`
   = note: required because it appears within the type `[closure@src/engine.rs:37:21: 41:22 engine:std::sync::Arc<engine::Engine>]`

error[E0277]: the trait bound `for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static: std::marker::Send` is not satisfied
  --> src/engine.rs:23:5
   |
23 | /     lazy_static! {
24 | |         static ref ENGINE: Arc<Engine> = {
25 | |             let engine = Arc::new(Engine {
26 | |                 events_loop: EventLoop::new(),
...  |
47 | |         };
48 | |     }
   | |_____^ `for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static` cannot be sent between threads safely
   |
   = help: the trait `std::marker::Send` is not implemented for `for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static`
   = note: required because of the requirements on the impl of `std::marker::Send` for `&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static`
   = note: required because of the requirements on the impl of `std::marker::Send` for `std::ptr::Unique<&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static>`
   = note: required because it appears within the type `alloc::raw_vec::RawVec<&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static>`
   = note: required because it appears within the type `std::vec::Vec<&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static>`
   = note: required because of the requirements on the impl of `std::marker::Send` for `std::sync::Mutex<std::vec::Vec<&'static mut for<'r> std::ops::FnMut(cpal::cpal_impl::VoiceId, cpal::UnknownTypeBuffer<'r>) + 'static>>`
   = note: required because it appears within the type `cpal::cpal_impl::ActiveCallbacks`
   = note: required because of the requirements on the impl of `std::marker::Send` for `std::sync::Arc<cpal::cpal_impl::ActiveCallbacks>`
   = note: required because it appears within the type `cpal::cpal_impl::EventLoop`
   = note: required because it appears within the type `cpal::EventLoop`
   = note: required because it appears within the type `engine::Engine`
   = note: required because of the requirements on the impl of `std::marker::Sync` for `std::sync::Arc<engine::Engine>`
   = note: required by `<engine::play_raw::ENGINE as std::ops::Deref>::deref::require_sync`
   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)