Add ARCHFLAGS to macOS installation command
Summary:
This PR solves the installation error `Unsupported architecture` on macOS.
Related Issues:
Pull Request resolved:
@@ -20,7 +20,7 @@ git clone https://github.com/facebookresearch/detectron2.git
python -m pip install -e detectron2
# Or if you are on macOS
-CC=clang CXX=clang++ python -m pip install ......
+CC=clang CXX=clang++ ARCHFLAGS="-arch x86_64" python -m pip install ......
```
To __rebuild__ detectron2 that's built from a local clone, use `rm -rf build/ **/*.so` to clean the
