Issues Building Elan on macOS 15.0 with XCode 16 on Intel: error: _Float16 is not supported on this target

[dbl001]

I'm trying to build 'elan' on macOS Sequoia and ran into an issue with float16 building OpenSSL.

% rustup update stable
info: syncing channel updates for 'stable-x86_64-apple-darwin'

  stable-x86_64-apple-darwin unchanged - rustc 1.81.0 (eeb90cda1 2024-09-04)

info: checking for self-update

% cargo build   
...

 In file included from ssl/quic/json_enc.c:14:
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/math.h:614:27: error: _Float16 is not supported on this target
  extern _Float16 __fabsf16(_Float16) __API_AVAILABLE(macos(15.0), ios(18.0), watchos(11.0), tvos(18.0));
                            ^
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/math.h:614:8: error: _Float16 is not supported on this target
  extern _Float16 __fabsf16(_Float16) __API_AVAILABLE(macos(15.0), ios(18.0), watchos(11.0), tvos(18.0));
         ^
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/math.h:615:28: error: _Float16 is not supported on this target
  extern _Float16 __hypotf16(_Float16, _Float16) __API_AVAILABLE(macos(15.0), ios(18.0), watchos(11.0), tvos(18.0));

...

 thread 'main' panicked at /Users/davidlaxer/.cargo/registry/src/index.crates.io-6f17d22bba15001f/openssl-src-300.3.1+3.3.1/src/lib.rs:621:9:



  Error building OpenSSL:
      Command: cd "/Users/davidlaxer/elan/target/debug/build/openssl-sys-53840312ddb82c05/out/openssl-build/build/src" && MAKEFLAGS="-j --jobserver-fds=8,9 --jobserver-auth=8,9" "make" "build_libs"
      Exit status: exit status: 2