Compile errors

[thewh1teagle]

I would like to use this crate for AEC (acoustic echo cancellation)
But it doesn't compile on macOS M1.

Also, why the sys feature is required for running the examples?
I wish we could use this tool without autotools or another packages. simply with CMake or another modern way to use C++ libraries. can we improve it? thanks.

error: failed to run custom build command for `speexdsp-sys v0.1.2 (/Volumes/Internal/piper-rs/speexdsp-rs/speexdsp-sys)`

Caused by:
  process didn't exit successfully: `/Volumes/Internal/piper-rs/speexdsp-rs/target/debug/build/speexdsp-sys-b959e567f4cae031/build-script-build` (exit status: 101)
  --- stdout
  cargo:rerun-if-env-changed=SPEEXDSP_NO_PKG_CONFIG
  cargo:rerun-if-env-changed=PKG_CONFIG_aarch64-apple-darwin
  cargo:rerun-if-env-changed=PKG_CONFIG_aarch64_apple_darwin
  cargo:rerun-if-env-changed=HOST_PKG_CONFIG
  cargo:rerun-if-env-changed=PKG_CONFIG
  cargo:rerun-if-env-changed=PKG_CONFIG_PATH_aarch64-apple-darwin
  cargo:rerun-if-env-changed=PKG_CONFIG_PATH_aarch64_apple_darwin
  cargo:rerun-if-env-changed=HOST_PKG_CONFIG_PATH
  cargo:rerun-if-env-changed=PKG_CONFIG_PATH
  cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR_aarch64-apple-darwin
  cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR_aarch64_apple_darwin
  cargo:rerun-if-env-changed=HOST_PKG_CONFIG_LIBDIR
  cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_aarch64-apple-darwin
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_aarch64_apple_darwin
  cargo:rerun-if-env-changed=HOST_PKG_CONFIG_SYSROOT_DIR
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR

  --- stderr
  thread 'main' panicked at speexdsp-sys/build.rs:27:10:
  called `Result::unwrap()` on an `Err` value: PkgConfig(
  pkg-config exited with status code 1
  > PKG_CONFIG_ALLOW_SYSTEM_CFLAGS=1 pkg-config --libs --cflags speexdsp speexdsp >= 1.2

  The system library `speexdsp` required by crate `speexdsp-sys` was not found.
  The file `speexdsp.pc` needs to be installed and the PKG_CONFIG_PATH environment variable must contain its parent directory.
  The PKG_CONFIG_PATH environment variable is not set.

  HINT: if you have installed the library, try setting PKG_CONFIG_PATH to the directory containing `speexdsp.pc`.
  )
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...