Linux build fails

[eye-wave]

Here's the build log after running tauri build ( warnings and notes were removed leaving only errors ).
tested on stable and nightly.

error[E0432]: unresolved import `libpulse_binding`
  --> src/output.rs:50:9
   |
50 |     use libpulse_binding as pulse;
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^ no external crate `libpulse_binding`

error[E0432]: unresolved import `libpulse_simple_binding`
  --> src/output.rs:51:9
   |
51 |     use libpulse_simple_binding as psimple;
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no external crate `libpulse_simple_binding`

error[E0050]: method `write` has 2 parameters but the declaration in trait `AudioOutput::write` has 4
   --> src/output.rs:112:18
    |
21  |     fn write(&mut self, decoded: AudioBufferRef<'_>, ramp_up_samples: u64, ramp_down_samples: u64);
    |              ------------------------------------------------------------------------------------ trait requires 4 parameters
...
112 |         fn write(&mut self, decoded: AudioBufferRef<'_>) -> Result<()> {
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 4 parameters, found 2

error[E0046]: not all trait items implemented, missing: `get_sample_rate`, `pause`, `resume`, `update_resampler`, `has_remaining_samples`, `ramp_down`, `ramp_up`
   --> src/output.rs:111:5
    |
23  |     fn get_sample_rate(&self) -> u32;
    |     --------------------------------- `get_sample_rate` from trait
24  |     fn pause(&self);
    |     ---------------- `pause` from trait
25  |     fn resume(&self);
    |     ----------------- `resume` from trait
26  |     fn update_resampler(&mut self, spec: SignalSpec, max_frames: u64) -> bool;
    |     -------------------------------------------------------------------------- `update_resampler` from trait
27  |     fn has_remaining_samples(&self) -> bool;
    |     ---------------------------------------- `has_remaining_samples` from trait
28  |     fn ramp_down(&mut self, buffer: AudioBufferRef, num_samples: usize);
    |     -------------------------------------------------------------------- `ramp_down` from trait
29  |     fn ramp_up(&mut self, buffer: AudioBufferRef, num_samples: usize);
    |     ------------------------------------------------------------------ `ramp_up` from trait
...
111 |     impl AudioOutput for PulseAudioOutput {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `get_sample_rate`, `pause`, `resume`, `update_resampler`, `has_remaining_samples`, `ramp_down`, `ramp_up` in implementation

error[E0061]: this function takes 2 arguments but 8 arguments were supplied
   --> src/player.rs:593:42
    |
593 |                     audio_output.replace(output::try_open(
    |                                          ^^^^^^^^^^^^^^^^
    |

error[E0308]: mismatched types
    --> src/player.rs:593:42
     |
593  |                       audio_output.replace(output::try_open(
     |  __________________________________-------_^
     | |                                  |
     | |                                  arguments to this method are incorrect
594  | |                         spec,
595  | |                         volume_control_receiver.clone(),
596  | |                         sample_offset_receiver.clone(),
...    |
601  | |                         app_handle.clone(),
602  | |                     ));
     | |_____________________^ expected `Result<Arc<Mutex<...>>, ...>`, found `Result<Box<dyn AudioOutput>, ...>`
     |
     = note: expected enum `std::result::Result<Arc<tokio::sync::Mutex<dyn AudioOutput>>, _>`
                found enum `std::result::Result<Box<(dyn AudioOutput + 'static)>, _>`
help: the return type of this call is `std::result::Result<Box<(dyn AudioOutput + 'static)>, AudioOutputError>` due to the type of the argument passed
    --> src/player.rs:593:21
     |
593  |                        audio_output.replace(output::try_open(
     |  ______________________^____________________-
     | | _____________________|
     | ||
594  | ||                         spec,
595  | ||                         volume_control_receiver.clone(),
596  | ||                         sample_offset_receiver.clone(),
...    ||
601  | ||                         app_handle.clone(),
602  | ||                     ));
     | ||_____________________-^
     | |______________________|
     |                        this argument influences the return type of `replace`

Some errors have detailed explanations: E0046, E0050, E0061, E0308, E0432.
For more information about an error, try `rustc --explain E0046`.
warning: `app` (bin "app") generated 49 warnings
error: could not compile `app` (bin "app") due to 6 previous errors; 49 warnings emitted
       Error failed to build app: failed to build app
error: script "tauri" exited with code 1

[basharovV]

Hi! Thanks for reporting (and trying out on Linux before I did!).

I think the PulseAudio code can be removed - I borrowed it from an example in the Symphonia repo but ideally this should work directly via cpal instead, which supports ALSA and JACK already so there is no need to have platform-specific audio handling in musicat. It appears that cpal uses ALSA by default on Linux, but jack can also be enabled via a feature flag.

You're welcome to submit a PR!

[basharovV]

I have removed the PulseAudio code, and created a Linux-specific tauri.linux.conf.json file. Tested on Ubuntu 20.04 and it builds successfully. Import and playback works, but on quick glance the UI looks off, WebRTC viz doesn't work due to lack of support in webkit2gtk. I'm sure there's more issues, need to test further