bug: rust ffmpeg crate fails to compile

[massivebird]

Man this shit sucks. I have vaapi.h-adjacent files from ffmpeg and some other package, but it's looking for the file(s) in /usr/include/, which doesn't even exist on my system.

Flake setup

  {
  description = "fallow: Jump King";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
  };

  outputs = { self, nixpkgs, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs {
          inherit system;
        };
      in
        with pkgs;
      {
        # `nix develop`
        devShell = mkShell {
          buildInputs = [
            cargo
            ffmpeg.dev
            llvmPackages.libclang.lib
            openssl
            pkg-config
            rustc
          ];

          shellHook = ''
            export LIBCLANG_PATH="${pkgs.llvmPackages.libclang.lib}/lib";
          '';
        };
      }
    );
}

Error message

  --- stderr
  Using stack size: Ok(3145728)
  In file included from /nix/store/cjmda5agi5ddwf4x43v7x20fm7p39047-glibc-2.40-66-dev/include/bits/libc-header-start.h:33,
                   from /nix/store/cjmda5agi5ddwf4x43v7x20fm7p39047-glibc-2.40-66-dev/include/stdio.h:28,
                   from check.c:2:
  /nix/store/cjmda5agi5ddwf4x43v7x20fm7p39047-glibc-2.40-66-dev/include/features.h:422:4: warning: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp]
    422 | #  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
        |    ^~~~~~~
  fatal error: '/usr/include/libavcodec/vaapi.h' file not found
  fatal error: '/usr/include/libavcodec/vaapi.h' file not found, err: true

  thread 'ffmpg-sys-build' panicked at /home/penguino/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/ffmpeg-sys-4.3.3/build.rs:1279:10:
  Unable to generate bindings: ()
  stack backtrace:
     0: rust_begin_unwind
     1: core::panicking::panic_fmt
     2: core::result::unwrap_failed
     3: core::result::Result<T,E>::expect
     4: build_script_build::thread_main
     5: core::ops::function::FnOnce::call_once
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

  thread 'main' panicked at /home/penguino/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/ffmpeg-sys-4.3.3/build.rs:629:10:
  called `Result::unwrap()` on an `Err` value: Any { .. }
  stack backtrace:
     0: rust_begin_unwind
     1: core::panicking::panic_fmt
     2: core::result::unwrap_failed
     3: build_script_build::main
     4: core::ops::function::FnOnce::call_once
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.