On Apple M1 hosts, pip install confluent-kafka failed because there were no arm64 wheels and the source build could not find the brew-installed librdkafka headers. The historical workaround was brew install librdkafka plus export C_INCLUDE_PATH=$(brew --prefix)/include and export LIBRARY_PATH=$(brew --prefix)/lib before pip install. The maintainers closed this for good by shipping macOS arm64 wheels in v1.9.2 (linux arm64 wheels in v2.1.0). The durable fix is pip install 'confluent-kafka>=1.9.2' and skip the env-var dance entirely.