The problem: after pip install aiven-client on a Mac, avn commands fail with SSLV3_ALERT_BAD_RECORD_MAC. Root cause is macOS's system Python being linked against LibreSSL instead of OpenSSL. System Python is also frozen at 3.9.6 on recent macOS, and aiven-client now requires Python 3.10+, so the system Python is unsupported either way.
What to do:
1. Install Python from Homebrew or python.org. Both ship Python linked against OpenSSL, not LibreSSL:
brew install openssl
brew reinstall python
2. Reinstall the client with the new Python: pip3 install aiven-client
3. certifi is a hard dependency, so you get a consistent CA bundle with the install. No manual cert juggling needed.
Dont try to patch the system Python in place; it cant be fixed there. Use your own Python for any CLI tooling that does TLS against cloud APIs.