Bindings generation are broken for cross-compilation on MacOS

Input C/C++ Header

#include <bzlib.h>

Bindgen Invocation

let bindings = bindgen::Builder::default()
        // The input header we would like to generate
        // bindings for.
        .clang_arg("--sysroot=/usr/local/Caskroom/android-ndk/21/android-ndk-r21/sysroot")
        .clang_arg("-I/usr/local/Caskroom/android-ndk/21/android-ndk-r21/sysroot/usr/include")
        .clang_arg("-I/usr/local/Caskroom/android-ndk/21/android-ndk-r21/sysroot/usr/include/arm-linux-androideabi")
        .header("src/wrapper.h")
        // Tell cargo to invalidate the built crate whenever any of the
        // included header files changed.
        .parse_callbacks(Box::new(bindgen::CargoCallbacks))
        // Finish the builder and generate the bindings.
        .generate()
        // Unwrap the Result and panic on failure.
        .expect("Unable to generate bindings");

or

Actual Results

vimmerru@Vyacheslavs-MacBook-Pro bindgen-test % RUST_BACKTRACE=1 cargo build  --target armv7-linux-androideabi
   Compiling bindgen-test v0.1.0 (/Users/vimmerru/Workspace/bindgen-test)
error: failed to run custom build command for `bindgen-test v0.1.0 (/Users/vimmerru/Workspace/bindgen-test)`

Caused by:
  process didn't exit successfully: `/Users/vimmerru/Workspace/bindgen-test/target/debug/build/bindgen-test-dcf2134524360bb7/build-script-build` (exit code: 101)
--- stdout
cargo:rustc-link-lib=bz2
cargo:rerun-if-changed=wrapper.h
cargo:warning=couldn't execute `llvm-config --prefix` (error: No such file or directory (os error 2))
cargo:warning=set the LLVM_CONFIG_PATH environment variable to the full path to a valid `llvm-config` executable (including the executable itself)

--- stderr
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/cdefs.h:807:2: error: Unsupported architecture
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/machine/_types.h:34:2: error: architecture not supported
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:55:9: error: unknown type name '__int64_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:56:9: error: unknown type name '__int32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:57:9: error: unknown type name '__int32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:60:9: error: unknown type name '__uint32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:61:9: error: unknown type name '__uint32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:62:9: error: unknown type name '__uint64_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:68:9: error: unknown type name '__darwin_natural_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:70:9: error: unknown type name '__uint16_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:71:9: error: unknown type name '__int64_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:72:9: error: unknown type name '__int32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:73:9: error: unknown type name '__uint32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:74:9: error: unknown type name '__int32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:75:9: error: unknown type name '__uint32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:76:9: error: unknown type name '__uint32_t'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/machine/types.h:37:2: error: architecture not supported
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types/_va_list.h:32:9: error: unknown type name '__darwin_va_list'
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types/_size_t.h:31:9: error: unknown type name '__darwin_size_t'
fatal error: too many errors emitted, stopping now [-ferror-limit=]
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/cdefs.h:807:2: error: Unsupported architecture, err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/machine/_types.h:34:2: error: architecture not supported, err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:55:9: error: unknown type name '__int64_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:56:9: error: unknown type name '__int32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:57:9: error: unknown type name '__int32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:60:9: error: unknown type name '__uint32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:61:9: error: unknown type name '__uint32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:62:9: error: unknown type name '__uint64_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:68:9: error: unknown type name '__darwin_natural_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:70:9: error: unknown type name '__uint16_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:71:9: error: unknown type name '__int64_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:72:9: error: unknown type name '__int32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:73:9: error: unknown type name '__uint32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:74:9: error: unknown type name '__int32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:75:9: error: unknown type name '__uint32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types.h:76:9: error: unknown type name '__uint32_t', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/machine/types.h:37:2: error: architecture not supported, err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types/_va_list.h:32:9: error: unknown type name '__darwin_va_list', err: true
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types/_size_t.h:31:9: error: unknown type name '__darwin_size_t', err: true
fatal error: too many errors emitted, stopping now [-ferror-limit=], err: true
thread 'main' panicked at 'Unable to generate bindings: ()', src/libcore/result.rs:1188:5
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /Users/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /Users/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:84
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:61
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1025
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1426
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:65
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:50
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:193
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:210
  10: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:471
  11: rust_begin_unwind
             at src/libstd/panicking.rs:375
  12: core::panicking::panic_fmt
             at src/libcore/panicking.rs:84
  13: core::result::unwrap_failed
             at src/libcore/result.rs:1188
  14: core::result::Result<T,E>::expect
             at /rustc/f3e1a954d2ead4e2fc197c7da7d71e6c61bad196/src/libcore/result.rs:983
  15: build_script_build::main
             at ./build.rs:17
  16: std::rt::lang_start::{{closure}}
             at /rustc/f3e1a954d2ead4e2fc197c7da7d71e6c61bad196/src/libstd/rt.rs:67
  17: std::rt::lang_start_internal::{{closure}}
             at src/libstd/rt.rs:52
  18: std::panicking::try::do_call
             at src/libstd/panicking.rs:292
  19: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:78
  20: std::panicking::try
             at src/libstd/panicking.rs:270
  21: std::panic::catch_unwind
             at src/libstd/panic.rs:394
  22: std::rt::lang_start_internal
             at src/libstd/rt.rs:51
  23: std::rt::lang_start
             at /rustc/f3e1a954d2ead4e2fc197c7da7d71e6c61bad196/src/libstd/rt.rs:67
  24: build_script_build::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

vimmerru@Vyacheslavs-MacBook-Pro bindgen-test % 

Expected Results

Bindings generated

Start with the reported build.rs invocation and src/wrapper.h, then reproduce cargo build --target armv7-linux-androideabi on macOS. Trace how bindgen::Builder handles the supplied sysroot and include paths, including the llvm-config warning; done means bindings are generated successfully for the cross-compilation target.