## The symptom
On macOS 13.x, `pip install chromadb` fails while building the hnswlib wheel
with clang errors like "unknown type name 'nullptr_t'" and "command
'/usr/bin/clang' failed with exit code 1". Multiple users hit this across
Python 3.9 through 3.11.
## Why
hnswlib compiles with native CPU-architecture flags that the toolchain cannot
handle, so the build blows up on Apple hardware regardless of Python version.
## The fix
Disable hnswlib's native-architecture flags before installing:
```
export HNSWLIB_NO_NATIVE=1
pip install chromadb
```
This was confirmed working by multiple reporters in the thread.
## Fallback
If that still fails, switching to Python 3.10.10 (which had prebuilt wheels at
the time) was another confirmed workaround. Prefer the env var first; it is the
less disruptive fix.