Build fails with `unrecognized command-line option '-arch'` when cross-compiling

Hi :-)

Has anyone seen anything like this before when cross-compiling on an M1 Mac?

This cross-compile configuration works successfully for a variety of other crates, however this is the first crate I'm using that uses CMake, so I'm not sure if it's a libz-sys specific problem, or with cross-compiling with CMake and this toolchain in general.

Steps to reproduce

1. brew install messense/macos-cross-toolchains/x86_64-unknown-linux-musl (to install this cross-compile toolchain)
2. brew install cmake (since libz-sys requires it)
3. rustup target add x86_64-unknown-linux-musl
4. Ensure the new toolchain can be found:

   export CC_x86_64_unknown_linux_musl=x86_64-unknown-linux-musl-gcc
   export CXX_x86_64_unknown_linux_musl=x86_64-unknown-linux-musl-g++
   export AR_x86_64_unknown_linux_musl=x86_64-unknown-linux-musl-ar
   export CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER=x86_64-unknown-linux-musl-gcc
   

5. cargo new testcase-libz-sys-cross-compile && cd_
6. cargo build --target x86_64-unknown-linux-musl

Expected

The build completes successfully (like it does on this machine, when not cross-compiling).

Actual

The build fails with:

   Compiling cc v1.0.73
   Compiling pkg-config v0.3.24
   Compiling libc v0.2.121
   Compiling cmake v0.1.48
   Compiling libz-sys v1.1.5
error: failed to run custom build command for `libz-sys v1.1.5`

Caused by:
  process didn't exit successfully: `/Users/emorley/src/testcase-libz-sys-cross-compile/target/debug/build/libz-sys-720c0d8a10ea6099/build-script-build` (exit status: 101)
  --- stdout
  cargo:rerun-if-env-changed=LIBZ_SYS_STATIC
  cargo:rerun-if-changed=build.rs
  CMAKE_TOOLCHAIN_FILE_x86_64-unknown-linux-musl = None
  CMAKE_TOOLCHAIN_FILE_x86_64_unknown_linux_musl = None
  TARGET_CMAKE_TOOLCHAIN_FILE = None
  CMAKE_TOOLCHAIN_FILE = None
  CMAKE_GENERATOR_x86_64-unknown-linux-musl = None
  CMAKE_GENERATOR_x86_64_unknown_linux_musl = None
  TARGET_CMAKE_GENERATOR = None
  CMAKE_GENERATOR = None
  CMAKE_PREFIX_PATH_x86_64-unknown-linux-musl = None
  CMAKE_PREFIX_PATH_x86_64_unknown_linux_musl = None
  TARGET_CMAKE_PREFIX_PATH = None
  CMAKE_PREFIX_PATH = None
  CMAKE_x86_64-unknown-linux-musl = None
  CMAKE_x86_64_unknown_linux_musl = None
  TARGET_CMAKE = None
  CMAKE = None
  running: "cmake" "/Users/emorley/.cargo/registry/src/github.com-1ecc6299db9ec823/libz-sys-1.1.5/src/zlib-ng" "-DBUILD_SHARED_LIBS=OFF" "-DZLIB_COMPAT=ON" "-DWITH_GZFILEOP=ON" "-DCMAKE_INSTALL_PREFIX=/Users/emorley/src/testcase-libz-sys-cross-compile/target/x86_64-unknown-linux-musl/debug/build/libz-sys-2b3ea8f924a72b91/out" "-DCMAKE_C_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_C_COMPILER=/opt/homebrew/bin/x86_64-unknown-linux-musl-gcc" "-DCMAKE_CXX_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_CXX_COMPILER=/opt/homebrew/bin/x86_64-unknown-linux-musl-g++" "-DCMAKE_ASM_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_ASM_COMPILER=/opt/homebrew/bin/x86_64-unknown-linux-musl-gcc" "-DCMAKE_BUILD_TYPE=Debug"
  -- Using CMake version 3.22.3
  -- ZLIB_HEADER_VERSION: 1.2.11
  -- ZLIBNG_HEADER_VERSION: 2.1.0.devel
  -- The C compiler identification is GNU 11.2.0
  -- Checking whether C compiler has -isysroot
  -- Checking whether C compiler has -isysroot - yes
  -- Checking whether C compiler supports OSX deployment target flag
  -- Checking whether C compiler supports OSX deployment target flag - no
  -- Detecting C compiler ABI info
  -- Detecting C compiler ABI info - failed
  -- Check for working C compiler: /opt/homebrew/bin/x86_64-unknown-linux-musl-gcc
  -- Check for working C compiler: /opt/homebrew/bin/x86_64-unknown-linux-musl-gcc - broken
  -- Configuring incomplete, errors occurred!
  See also "/Users/emorley/src/testcase-libz-sys-cross-compile/target/x86_64-unknown-linux-musl/debug/build/libz-sys-2b3ea8f924a72b91/out/build/CMakeFiles/CMakeOutput.log".
  See also "/Users/emorley/src/testcase-libz-sys-cross-compile/target/x86_64-unknown-linux-musl/debug/build/libz-sys-2b3ea8f924a72b91/out/build/CMakeFiles/CMakeError.log".

  --- stderr
  CMake Error at /opt/homebrew/Cellar/cmake/3.22.3/share/cmake/Modules/CMakeTestCCompiler.cmake:69 (message):
    The C compiler

      "/opt/homebrew/bin/x86_64-unknown-linux-musl-gcc"

    is not able to compile a simple test program.

    It fails with the following output:

      Change Dir: /Users/emorley/src/testcase-libz-sys-cross-compile/target/x86_64-unknown-linux-musl/debug/build/libz-sys-2b3ea8f924a72b91/out/build/CMakeFiles/CMakeTmp

      Run Build Command(s):/usr/bin/make -f Makefile cmTC_710b5/fast && /Library/Developer/CommandLineTools/usr/bin/make  -f CMakeFiles/cmTC_710b5.dir/build.make CMakeFiles/cmTC_710b5.dir/build
      Building C object CMakeFiles/cmTC_710b5.dir/testCCompiler.c.o
      /opt/homebrew/bin/x86_64-unknown-linux-musl-gcc   -ffunction-sections -fdata-sections -fPIC -m64  -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX12.3.sdk -std=c11 -o CMakeFiles/cmTC_710b5.dir/testCCompiler.c.o -c /Users/emorley/src/testcase-libz-sys-cross-compile/target/x86_64-unknown-linux-musl/debug/build/libz-sys-2b3ea8f924a72b91/out/build/CMakeFiles/CMakeTmp/testCCompiler.c
      x86_64-unknown-linux-musl-gcc: error: unrecognized command-line option '-arch'
      make[1]: *** [CMakeFiles/cmTC_710b5.dir/testCCompiler.c.o] Error 1
      make: *** [cmTC_710b5/fast] Error 2

    CMake will not be able to correctly generate this project.
  Call Stack (most recent call first):
    CMakeLists.txt:37 (project)

  thread 'main' panicked at '
  command did not execute successfully, got: exit status: 1

  build script failed, must exit now', /Users/emorley/.cargo/registry/src/github.com-1ecc6299db9ec823/cmake-0.1.48/src/lib.rs:975:5
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Environment

• macOS 12.3 on Apple Silicon (M1 Max)
• rustc 1.60.0-beta.6 (7bccde197 2022-03-22)
• Crate versions at time of testing:
  • libz-sys: 1.1.5
  • cmake: 0.1.48
  • pkg-config: 0.3.24
• The cross-compile toolchain currently uses GCC 11.2.

Start with build.rs and the CMake configuration referenced at CMakeLists.txt:37, then reproduce the command shown in the issue with the x86_64-unknown-linux-musl toolchain. Check the CMake compiler-detection output and determine what causes the cross-compiler to receive -arch; done means the cargo build completes successfully for that target.