Build fails on macOS ARM64 with cerrno header not found

[Omer80]

Environment

• OS: macOS (arm64)
• Python version: 3.12
• Annoy version: 1.17.3
• Compiler: clang++

Issue Description

When trying to install annoy via pip, the build fails with a compilation error indicating that the cerrno header file cannot be found.

Steps to Reproduce

1. Create a virtual environment
2. Run pip install annoy==1.17.3

Error Output

Collecting annoy==1.17.3
Using cached annoy-1.17.3.tar.gz (647 kB)
Installing build dependencies ... done
Getting requirements to build wheel ... done
Installing backend dependencies ... done
Preparing metadata (pyproject.toml) ... done
Building wheels for collected packages: annoy
Building wheel for annoy (pyproject.toml) ... error
error: subprocess-exited-with-error
× Building wheel for annoy (pyproject.toml) did not run successfully.
│ exit code: 1
╰─> [output]
running bdist_wheel
running build
running build_py
creating build/lib.macosx-10.13-universal2-cpython-312/annoy
copying annoy/init.py -> build/lib.macosx-10.13-universal2-cpython-312/annoy
copying annoy/init.pyi -> build/lib.macosx-10.13-universal2-cpython-312/annoy
copying annoy/py.typed -> build/lib.macosx-10.13-universal2-cpython-312/annoy
running build_ext
building 'annoy.annoylib' extension
creating build/temp.macosx-10.13-universal2-cpython-312/src
clang++ -fno-strict-overflow -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -O3 -Wall -arch arm64 -arch x86_64 -g -I/Users/user/code/livekit-apps/livekit-rag-thinking/venv/include -I/Library/Frameworks/Python.framework/Versions/3.12/include/python3.12 -c src/annoymodule.cc -o build/temp.macosx-10.13-universal2-cpython-312/src/annoymodule.o -D_CRT_SECURE_NO_WARNINGS -fpermissive -O3 -ffast-math -fno-associative-math -DANNOYLIB_MULTITHREADED_BUILD -std=c++14 -mmacosx-version-min=10.12
In file included from src/annoymodule.cc:15:
src/annoylib.h:53:10: fatal error: 'cerrno' file not found
53 | #include <cerrno>
| ^~~~~~~~
1 error generated.
error: command '/usr/bin/clang++' failed with exit code 1

Additional Context

The error occurs during the compilation phase when trying to build the C++ extension. The compiler is unable to find the standard C++ header cerrno. This might be related to the macOS SDK path configuration or C++ standard library installation.

Possible Related Issues

• This might be related to the minimum macOS version being set to 10.12 (-mmacosx-version-min=10.12) while building on a newer system
• The universal2 build attempting both arm64 and x86_64 architectures might be contributing to the issue

Would appreciate any guidance on resolving this compilation error.

[sloggiz]

hey! I had the exact same issue and I managed to solve it:

1. Install gcc first:
   brew install gcc
2. Then check the installed version:
   ls /opt/homebrew/bin/gcc-*
3. You should see an output like:
   /opt/homebrew/bin/gcc-14
4. Based on the output set the following env variables:
   export CC=/opt/homebrew/bin/gcc-14
export CXX=/opt/homebrew/bin/g++-14
5. Try to re-install annoy (I didn't use a fixed version though)